Keeping up with HMC Clinic project

[Martin]

o3 Deep Research main response (part 2 of 3)

4. Best Platinum Plating Solutions

The choice of plating solution greatly affects the consistency and quality of the platinum deposit. It is important to use a commercial, high-purity platinum plating solution that is formulated for repeatable results. Key considerations include the platinum chemical form, bath composition (acidity, additives), and ease of use. Here we outline the top options:

• Acid-Based Platinum Baths (P-Salt or Similar): Most platinum electroplating solutions are based on chloroplatinic acid or platinum amine complexes (often called “P-salt”, e.g. platinum diamino dinitrite). These are typically used with a strong acid like sulfuric or sulfamic acid as supporting electrolyte (Titanium platinum plating question | Gold Refining & Metal Extraction Forum). A quality commercial solution will contain the correct concentration of Pt (usually 2–10 g/L) and proprietary additives that improve plating characteristics (throwing power, brightness, stress). For example, a ready-to-use platinum bath might contain ~4 g/L Pt as complex salt and plate deposits from 0.2 up to 20 µm with uniform thickness (P52510 | Platinum Plating Solution). This type of solution produces a dense, pure platinum layer (bright white to light grey in appearance) (P52510 | Platinum Plating Solution). We recommend using these standard platinum plating baths as they are well-characterized and free of hazardous additives like cyanide (common in gold plating, but not needed for Pt).

• Recommended Commercial Solutions: Several reputable suppliers provide platinum plating solutions suitable for our application:

  • Spa Plating (Goldn) – Platinum Tank Plating Solution. This UK-based supplier (Spa Plating Ltd.) is known for plating kits for hobbyists and researchers. Their platinum bath is designed for tank plating (immersive plating) and is available in small quantities (50 mL up to 250 mL) (Platinum - Electroplating equipment). Users in the AMYBO project have liaised with Spa Plating; the company even provided custom platinum-coated electrodes and pointed to their platinising process videos (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org). Spa Plating’s solution is formulated for consistent deposition and good adhesion on difficult substrates. It’s a convenient choice, especially in the UK/EU, to ensure everyone is using the same solution chemistry. Purchase from their official site (goldn.co.uk) or authorized distributors.
  • Legor / Technoplate Platinum Solutions – Legor is an Italian company whose plating solutions are distributed worldwide (e.g. via Cousins UK, Rio Grande, Stuller, etc.). Their platinum plating solution (often called PTLUX or similar) is a high-quality bath used in the jewelry industry for decorative platinum plating. It produces uniform coatings and is free of nickel, lead, cadmium (P52510 | Platinum Plating Solution) (important for avoiding contamination). A 1 L bottle (with ~4 g Pt) is ~£195 (P52510 | Platinum Plating Solution). The Legor bath is known for bright, adherent platinum deposits and could be an excellent choice for research electrodes due to its reliability. If multiple labs coordinate, using the same batch of Legor solution would standardize results.
  • “Rhoduna PT One” (Platinum-Rhodium) Solutions: For completeness, some commercially available solutions are mixed metal (platinum-rhodium) intended as rhodium plating substitutes (Rhoduna® PT One Rhodium Platinum Plating Solution - TP1311). For example, Rhoduna PT One contains a small amount of platinum in a rhodium bath. These are not recommended for our purpose – they are meant for thin decorative coatings and contain rhodium (which we don’t need and which could alter electrode properties). Stick to pure platinum solutions unless a specific reason to alloy is identified.
  • Other Suppliers: Companies like Johnson Matthey and Metalor historically offered platinum plating concentrates (“P-salt” based). Canning/Enthone (now MacDermid Enthone) also had platinum baths. For global labs, ensure the solution is equivalent in concentration and type. If one lab must use a local product, verify the platinum content and operating conditions match those of the standard solution (P52510 | Platinum Plating Solution).

• Solution Operating Conditions: The chosen plating solution will come with a technical data sheet. Adhering to its recommendations ensures consistency. Typical conditions for platinum plating:

  • Temperature: Many platinum baths operate at room temperature (20–30 °C). Some may allow slight heating (up to ~50 °C) to improve deposition rate or adhesion. Check the product guidelines – for example, Legor’s solution likely works at room temp (no special heating required), simplifying setup.
  • Current Density: Platinum plating often works in the range of 0.5–5 A/dm² (amps per square decimeter) depending on bath chemistry (Titanium platinum plating question | Gold Refining & Metal Extraction Forum). This roughly translates to 5–50 mA/cm². A moderate current density (e.g. ~10 mA/cm²) is a good starting point for a 2.5 µm deposit – it balances plating speed with deposit quality. Too high current can cause rough or dark deposits; too low can lead to poor adhesion. The solution manual will specify an optimum range.
  • Anodes: Use insoluble anodes with these solutions (usually platinized titanium or pure platinum anodes). Do not use a soluble platinum anode expecting it to dissolve to replenish platinum – Pt anodes are extremely corrosion-resistant and won’t appreciably dissolve under plating conditions (Microsoft Word - Surface World Article - Web Copy 27.03.07.doc). Thus, the bath’s Pt content will deplete after plating many parts; you’ll need to add replenisher or fresh solution eventually. For consistency, it’s best if all labs use fresh solution or solutions of the same age/usage level for a given experimental series.

• Consistency and Durability: The recommended solutions produce pure platinum deposits that are adherent and stable. They do not include significant hardeners or brighteners (common in decorative plating) that could embrittle the coating. The result is a coating that behaves like bulk platinum – high melting point, insoluble in most acids, and non-reactive, which is ideal for in-culture electrodes. Over time, if the plating solution is reused, impurities could accumulate (especially if plating multiple electrodes in batches). To maintain consistency worldwide, labs should either:

  • Use new solution for each batch of electrodes or,
  • Implement a standard maintenance routine (e.g. carbon treatment, or filtering of the bath after use) and document how many electrodes have been plated with a given solution volume.

In summary, for best results use a commercial platinum plating solution from a reputable source, such as Spa Plating’s Platinum Tank solution or an equivalent high-purity bath. This ensures that every lab is effectively working with the same chemistry, minimizing variation. Avoid homemade concoctions or repurposed jewelry baths without validation – the goal is a proven solution with published parameters that everyone can follow for identical outcomes. By standardizing the plating solution, we eliminate one major source of variability in electrode fabrication.

5. Surface Preparation of Titanium Rods

Proper surface preparation of the titanium rod is arguably the most critical step to achieve a well-adhered, uniform platinum coating. Titanium is a reactive metal that forms a tenacious oxide layer (TiO₂) which can prevent metal plating from bonding. Therefore, we must thoroughly clean and activate the surface. Below is the step-by-step optimal procedure for prepping 6 mm Ti rods:

5.1. Mechanical Cleaning and Shaping:

1. Cut to Length: Ensure each rod is cut to 60 mm length (if not already precut). Use a metal saw or cutting wheel suited for titanium. Deburr the cut edges with a file or sandpaper to remove any burrs or sharp edges.
2. Mark Plating Area: Mark the rod at 35 mm from one end (this end will be plated). You can use a fine marker or a scoring tool. This is a guide; actual plating will only occur where the solution contacts, but marking helps with handling and masking.
3. Surface Roughening (if needed): Lightly abrade the plating end (35 mm) of the rod with fine-grit abrasive paper (~400–600 grit). The goal is to create a matte surface by removing any heavy oxide and exposing fresh titanium. Do not overly scratch or gouge – just a gentle uniform matt finish. This can improve plating “keying” into the surface. Note: Some protocols skip mechanical abrasion and rely solely on chemical etch; however, a light abrasion can improve wetting and adhesion, especially if the Ti was very smooth or polished.
4. Masking: Mask the upper part of the rod (the 25 mm that will not be plated) to keep it clean and unetched. Use acid-resistant tape (e.g. PTFE tape or polyimide Kapton tape) wrapped just above the 35 mm mark. Also mask the very tip of the rod if it’s not needed to be plated (optional; in most cases we plate the entire 35 mm end including the tip). Ensure no adhesive overlaps into the area to be plated.

5.2. Degreasing:
5. Solvent Wash: Clean the exposed titanium surface with a solvent to remove oils. Soak a lint-free wipe or cotton in acetone and thoroughly wipe the plating end. Alternatively, dip the rod in acetone for a few minutes. This removes grease, marker ink, and organic residues.
6. Detergent Clean: Prepare a warm solution of lab-grade detergent or a few drops of dish soap in distilled water. Scrub the titanium end using a soft brush or toothbrush. If available: use an ultrasonic cleaner – submerge the rod in a beaker with the detergent solution and sonicate for 5–10 minutes. This knocks off fine particulates and any remaining oils.
7. Rinse: Rinse the rod very well in distilled (or deionized) water. It’s important to remove all soap and solvent residues. Hold the rod with clean tweezers or gloved hands (to avoid re-contaminating with skin oils).

8. (Optional Check – Water Break Test): After rinsing, observe the water wetting on the titanium surface. A fully clean metal surface will allow water to form an unbroken film. If the water beads up significantly (“water break”), it indicates remaining oil – repeat the cleaning steps if so.

5.3. Chemical Etching (Activation):
This is the critical activation to remove the passive TiO₂ layer and expose fresh titanium for plating. Caution: These steps involve corrosive acids. Wear proper PPE and work in a ventilated area or fume hood.

There are a few methods; the optimal one uses a brief HF-containing etch. If HF use is possible in your lab, follow Method A. If HF is not allowed, use Method B (slightly less effective, but safer).

• Method A: Acid Pickle with HF/HNO₃ (Preferred if possible) – This is a common activation for titanium:

  1. Prepare a pickling solution of hydrofluoric acid and nitric acid. A typical mixture (from literature and industry practice) is: HF (40%) 50 g/L and HNO₃ (67%) 400 g/L in water (Titanium platinum plating question | Gold Refining & Metal Extraction Forum). In simpler terms, roughly 1 part concentrated HF to 8 parts concentrated nitric, diluted in ~10 parts water. Example: 50 mL HF + 400 mL HNO₃ + 550 mL water. Always add acids to water and HF last. This mixture will vigorously attack oxides and slightly etch titanium metal.
  2. At room temperature, immerse the titanium end into the pickle solution for about 1–2 minutes (Titanium platinum plating question | Gold Refining & Metal Extraction Forum). You will see bubbling as the oxide dissolves. Do not exceed ~2 min to avoid excessive metal loss.
  3. Remove the rod and immediately rinse in copious distilled water. It’s crucial to wash off all HF/HNO₃. Do not allow the rod to dry with acid on it – rinse directly from the acid into water.
  4. (Optional) Follow with a second dip in a hot de-oxidizing acid: e.g. boiling in 5–10% oxalic acid for a few minutes (Titanium platinum plating question | Gold Refining & Metal Extraction Forum). This can further remove any remaining films and help condition the surface. Rinse again.

  This HF/Nitric treatment aggressively removes the oxide and activates the surface. Many successful Pt plating processes on Ti use exactly this step (Titanium platinum plating question | Gold Refining & Metal Extraction Forum) (Titanium platinum plating question | Gold Refining & Metal Extraction Forum). Ensure you proceed to plating (or at least the strike plating) immediately after this activation to avoid re-oxidation (titanium will form a new oxide layer within minutes in air).

• Method B: Fluoride Activation without HF – If HF is too hazardous or unavailable, a substitute is to use ammonium bifluoride (NH₄HF₂) or fluoride salt in acid:

  1. Prepare a solution of ammonium bifluoride ~10 g/L in 10% sulfuric acid (Titanium platinum plating question | Gold Refining & Metal Extraction Forum). Heat to about 50–60 °C to increase effectiveness, or use it at room temp for a longer time.
  2. Immerse the titanium end for ~5–10 minutes. The fluoride will slowly attack the oxide, and the acidic environment helps.
  3. Alternatively, use a solution of oxalic acid (80–100 g/L) at boil, as tried in experiments (Titanium platinum plating question | Gold Refining & Metal Extraction Forum). Boil the rod in that solution for ~10–15 min. Oxalic acid can chelate titanium and remove oxide to some extent.
  4. Rinse thoroughly in distilled water.

  This method is gentler and safer (ammonium bifluoride releases some HF in solution, but in a controlled manner). However, the titanium surface may not be as active as with the strong HF dip. It may suffice for plating if followed immediately by a plating strike. It’s recommended to not skip at least some fluoride-based activation; titanium surfaces treated only with nitric or hydrochloric acid without fluoride often still don’t plate well (the oxide isn’t fully removed).

5.4. Immediate Plating or Strike:
After the acid activation, do not delay. The rod should go straight into the plating bath (or a pre-plating strike bath) within minutes of etching:

• If you have a separate platinum strike solution (a dilute plating bath used for initial seeding), use it as per instructions. Most will simply use the main plating solution for both strike and plate.
• Keep the rod wet from the rinse; do not dry it (drying can allow oxygen to form oxide). It’s okay if some water is on it as it goes into the plating solution – the small amount will be inconsequential in a reasonably sized plating bath.

5.5. Summary of Key Points for Prep:

• Cleanliness is paramount: any grease or oxide will cause poor adhesion (the Pt can flake off easily). The rod should be chemically clean and active.
• Use fresh gloves and clean tools for handling post-etch. Avoid touching the etched area with fingers or contaminated tweezers.
• Consistency: All labs should follow the same prep protocol. The biggest variability in plating often comes from surface prep differences. By standardizing on, say, “abrade, solvent clean, HF/HNO₃ dip 60 s, rinse, plate immediately”, you ensure everyone’s titanium surface is in a similar state at the moment of plating.

Safety Notes: HF is very dangerous (causes deep burns and systemic toxicity). Only use it if trained and with proper facilities (fume hood, Ca-gluconate gel on standby). If labs cannot use HF, Method B provides a workable alternative using more benign chemicals. Even with Method B, wear gloves and eye protection; ammonium bifluoride and hot acids can also cause injuries.

By meticulously preparing the titanium surface as above, you create the ideal conditions for the platinum to adhere strongly rather than just “paint on”. A well-prepared titanium will yield electrodes that withstand handling, sterilization, and long-term operation without the platinum layer peeling or flaking.

6. Plating Thickness and Uniformity Verification

After plating the titanium rods with platinum, it’s important to verify that the coating thickness is as intended (~2.5 µm, or your target) and that it’s uniform along the 35 mm plated section. We outline both low-cost methods suitable for basic labs and high-end methods for thorough characterization:

6.1. Low-Cost Verification Methods:

• Gravimetric Calculation (Weighing Method): This is an accessible way to estimate average plating thickness:

  1. Weigh each rod before plating (after prep and drying) using a precision balance. Record the weight.
  2. Weigh the rod after plating (and rinsing/drying). The difference in weight is the mass of platinum deposited.
  3. Calculate the thickness using the formula derived from volume = mass/density. The surface area plated is the cylindrical area (excluding masked parts) plus the tip if plated. For a 6 mm diameter rod, 35 mm length: area ≈ 6 mm × π × 35 mm = 659 mm² (not counting the circular end of ~28 mm², add that if tip plated). Convert to cm² (6.59 cm² for side, 0.28 cm² for tip).
  4. Platinum density is 21.45 g/cm³. So thickness (cm) = mass of Pt (g) / (density * area (cm²)). For example, if 0.035 g Pt was deposited on 6.59 cm², thickness = 0.035 / (21.45 * 6.59) = 0.000245 cm = 2.45 µm.

  This method effectively applies the known relationship: mass = area × thickness × density (How to Estimate Gold Content in Gold Plated Parts - A.G. Metals). It provides an average thickness over the entire plated area (MEASURING THE THICKNESS OF THE SILVER LAYER WHEN …). Do this for each electrode – identical plating runs should show very similar mass gains (within a few milligrams). If one electrode gained significantly less or more mass, that indicates a plating issue (e.g. contact problem or different current distribution).

• Visual and Microscopic Inspection: Examine the plated surface:

  • Color/Appearance: A properly plated platinum layer will be metallic and silvery. It might be matte gray or slightly shiny white depending on plating parameters. Any discoloration (brown, black) or patchiness suggests problems (burnt deposit or thin areas). The AMYBO test noted that a failing electrode caused solution discoloration and itself looked “worse for wear” (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org), whereas a good Pt electrode stayed bright (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org) (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org).
  • Uniformity along length: Check if the plating is even from the tip to the 35 mm mark. Non-uniform current can cause gradients (e.g. thicker at the tip if it’s closer to the anode). If one end looks noticeably different, adjustments in anode placement or agitation might be needed. All labs should note any such visual cues for uniformity.
  • Microscope Check (if available): Under a 10x or 20x magnification (stereo microscope or a loupe), examine the surface texture. It should look continuous. You may see tiny nodules (common in electroplated Pt) but you should not see exposed titanium (which would look darker/different). If you have access to a metallographic microscope, you could cross-section one sacrificial rod to measure the coating – but this destroys that sample, so gravimetric or XRF methods are preferred for routine checks.

• Thickness Gauges: There are affordable handheld coating thickness gauges, but most work on ferrous/non-ferrous magnetic properties (for paint on steel, etc.) and are not suitable for Pt on Ti (both are non-ferromagnetic metals). Eddy current probes calibrated for non-magnetic coatings on non-magnetic substrates exist but are expensive. So, most low-cost gauges won’t help here.

• Adhesion Tests: While not a direct thickness measurement, a simple adhesion test ensures the plating is sound. Gently try to scrape the surface with a plastic spatula or apply tape and peel. A well-adhered 2–3 µm platinum won’t budge or flake under tape (assuming surface prep was done well). If plating flakes off easily, something went wrong in prep or plating (and thickness might effectively be zero in places). Perform this test on one of the electrodes (or a test piece) – it’s a quick qualitative check for uniform coverage.

6.2. High-End Verification Methods:

• X-Ray Fluorescence (XRF) Analysis: XRF is a non-destructive method widely used for coating thickness measurement (Plating Thickness Measurements - Applied Technical Services). An XRF analyzer can be calibrated to measure platinum thickness on titanium by detecting the intensity of Pt X-rays vs Ti substrate X-rays. Many plating shops or material labs have XRF equipment (following ASTM B568 for plating thickness (ASTM B568 - Plating Thickness By XRF Testing Services |)). XRF can measure even sub-micron coatings with good accuracy and can be done at multiple points along the rod to check uniformity. If resources allow, send one or two sample electrodes for XRF testing – it will confirm thickness (e.g. “2.4 µm Pt on Ti”) and uniform coverage. This is the gold standard for nondestructive testing (How to Measure Metal Coating Thickness Using Handheld X-ray …).

• Electron Microscopy (SEM/EDS): For a detailed analysis, one electrode can be cross-sectioned (e.g. cut a small piece of the plated end) and examined in a Scanning Electron Microscope. The platinum layer will be clearly distinguishable, and one can directly measure its thickness in the SEM image. Energy-dispersive X-ray spectroscopy (EDS) can map Pt vs Ti to ensure there are no gaps. This method is destructive (sacrifices the sample piece), but provides visual confirmation of thickness and adhesion (you may see if there’s a clear interface or any delamination). This is likely overkill for routine checks, but could be done by one lab and shared as a reference with others (e.g. “SEM shows ~2.5 µm dense Pt, with good adhesion”).

• Coulometric Stripping (Destructive): This method involves stripping the platinum off by electrochemical dissolution while monitoring charge. There are instruments that do this for plating thickness (often used for zinc or nickel plating tests). Platinum can be dissolved anodically in aqua regia or a specific electrolyte; the charge required corresponds to the metal mass, thus thickness. Given platinum’s noble nature, this isn’t as straightforward as for less noble metals, and it destroys the coating. It’s generally not used unless you specifically want to test one sample thoroughly.

• Precision Mechanical Measurement: If one has a high-precision micrometer (resolution 1 µm or better) and a consistent way to measure the rod diameter, one could measure diameter before and after plating. The diameter increase will be twice the coating thickness. For example, a 6.000 mm rod might become 6.005 mm if 2.5 µm plating (because 2×2.5 µm = 5 µm diameter increase). This requires extremely precise instruments and temperature control (to avoid thermal expansion differences). It’s generally at the edge of what affordable tools can discern (220 Methods of Thickness Test for Plate Coating), so we don’t rely on this except as a rough sanity check if such micrometers are at hand.

6.3. Uniformity Considerations:

• When plating multiple electrodes together (or sequentially in the same bath), uniformity between electrodes is also important. Compare the weights of all electrodes: they should be within, say, ±5% of the average if plating was consistent. If one is an outlier, investigate if its position or connection was different.
• In use, a uniform platinum coating means each electrode will behave similarly in the electroPioreactor (e.g. similar overpotential for hydrogen or oxygen evolution). If one electrode had thinner coating, it might show higher voltage or some corrosion of Ti. So verification isn’t just academic – it directly ties to experimental reproducibility.

Documentation: Each lab should document the plating thickness verification for their batch. For example, record pre/post weights and calculate thickness for a couple of electrodes, and maybe include a photo under magnification. This provides confidence that “Lab A’s electrodes” and “Lab B’s electrodes” truly have the same platinum loading. If any lab finds discrepancy, they can adjust their process (time or current in plating) accordingly.

By employing these verification methods, both simple and advanced, we can ensure that the electrodes meet the design specification (e.g. a ~2.5 µm Pt coating uniformly on 35 mm of each rod). Consistent verification across labs closes the loop in standardizing the electrode production.

TBC

[Martin]

o3 Deep Research main response (part 3 of 3)

7. Producing 12 Matched Electrodes for Academic Trials

When producing a larger batch (e.g. 12 electrodes) for multi-lab trials or comparative experiments, the process must be highly repeatable so that all electrodes are as identical as possible. Below is a detailed, repeatable method for plating 12 titanium rod electrodes in one run or in consistent sub-batches:

7.1. Batch Preparation:

• Material Prep: Obtain 12 titanium rods from the same source lot if possible to ensure identical composition and surface condition. Number or mark each rod (e.g. 1–12) on the unplated end for tracking.

• Follow Surface Prep (Section 5) meticulously for each rod: It’s best to process all rods together in each step to maintain consistency. For instance, degrease all 12, then etch all 12 in one acid bath (using a holder or doing a few at a time in quick succession). Use fresh cleaning solutions as needed (don’t let one rod’s dirt redeposit on another). If using HF etch, you can dip multiple rods at once using a Teflon rack or by holding several with PTFE string—just ensure equal exposure time (Titanium platinum plating question | Gold Refining & Metal Extraction Forum).

• Setup Plating Bath: Use a plating vessel large enough to accommodate all 12 rods at once or be prepared to plate in smaller batches (e.g. 3–4 at a time) with identical conditions. Plating all 12 simultaneously is ideal for uniformity, but requires a bit more setup:

  • Arrange an inert anode (or multiple anodes) so that each cathode (Ti rod) “sees” a similar anode-to-cathode distance. For example, you can use a platinized titanium mesh sheet bent into a cylindrical shape surrounding the rods, or a pair of mesh strips on either side of a row of rods, to provide even current distribution.
  • Mount the 12 rods on a non-conductive rack or holder. Ensure they are parallel, separated (no touching each other), and all dipped to the same depth (35 mm). A possibility: drill 6 mm holes in a plastic bar as a holder, or 3D-print a jig, to hold rods in place.
  • Connect all rods electrically together to the power supply’s negative output. This can be done by clamping all their unplated ends with a single bus bar or using wires that join to a common node (make sure the contact resistance to each rod is low and similar – tighten screws or clips firmly).
  • Essentially, you create a “cathode tree” of 12 identical parts.

• Solution Volume: Use a sufficient volume of plating solution so that the total platinum in solution can plate all rods without significant depletion. For 12 rods at ~0.035 g Pt each (for ~2.5 µm), that’s ~0.42 g Pt total. If your solution has 4 g/L, use at least 0.5 L (which has ~2 g Pt) so that even after plating, plenty of Pt remains in solution (and the concentration drop is at most 20%). This ensures plating rate doesn’t slow toward the end and all rods get the same environment. Alternatively, if using a smaller volume, you may need to replenish the solution with concentrate after a certain number of rods – but in one simultaneous batch, that’s not possible, so better to use a sufficiently sized bath initially.

7.2. Plating Process (for batch):

• Constant Current Plating: For best uniformity, use a constant current source and divide the current among the 12 rods. First, calculate the total area to be plated: one rod ~6.59 cm² (side) + ~0.28 cm² (tip) ≈ 6.87 cm². Twelve rods ~82.5 cm² total. Decide on a current density (say 10 mA/cm² as a moderate value). That would require ~0.825 A total current for 82.5 cm². Set the power supply to current-control mode at 0.825 A. If your supply can’t output that high, use a lower current density (5 mA/cm² → 0.412 A total). Make sure the anode area is ample so it can supply this current without polarization issues (platinum mesh has high capacity).

• Begin Plating: With rods immersed and all connections double-checked, turn on the current. Bubbles (hydrogen at cathodes) will evolve; gentle agitation helps dislodge them so they don’t cause bare spots. You can manually stir the solution or use a magnetic stir bar. Ensure all rods are bubbling similarly – this is a visual cue that current is distributed evenly.

• Time Control: Plate for the calculated time to reach desired thickness. Using Faraday’s law: the charge (Q) needed = area × thickness × density × (F/z/M) basically, but easier is to use the known plating efficiency if given. Many platinum baths have ~>90% cathode efficiency. For simplicity, one can empirically time based on earlier single tests or weight targets. For example, if one rod needed 15 minutes at 10 mA/cm² to get ~2.5 µm, then 12 rods at same current density also need ~15 minutes (since each cm² gets the same current density, the plating rate per area is the same). Monitor the process but avoid stopping midway (an interruption can sometimes cause oxidation or slight variation unless handled carefully).

• Rotation (if needed): If you suspect slight unevenness (rods closer to an anode plate might get more current), you can rotate the rod holders halfway through plating to even it out – but if the anode setup is symmetric, this shouldn’t be necessary.

• Completion: Once the time or charge is reached, turn off the current. Do not over-plate excessively as very thick deposits can introduce stress. Remove the rods from the bath promptly.

• Rinsing: Immediately rinse all plated rods in a large volume of distilled water. This removes residual acidic solution and prevents any chemical attack or staining. Then rinse in deionized water. Handle rods gently; though platinum is deposited, it’s best not to knock them together to avoid any potential mechanical damage when freshly plated.

• Post-Treatment: Some platers recommend a post-plating heat treatment for adhesion (e.g. annealing in hydrogen at ~700 °C as mentioned in literature for Pt/Ti) (Titanium platinum plating question | Gold Refining & Metal Extraction Forum) (Titanium platinum plating question | Gold Refining & Metal Extraction Forum). However, this is usually not feasible in most labs and likely unnecessary if prep and plating were done well. Our electrodes should have good adhesion as-is. You may simply dry the rods (air dry or gentle blow dry). If any plating solution components tend to stain, a dip in very dilute nitric acid can neutralize residues (though with modern platinum baths this isn’t usually an issue).

7.3. Ensuring Reproducibility:

• Characterize one or two rods: Take weight measurements of a couple of rods to ensure thickness met the target (Section 6). If the result is slightly off, you can adjust plating time for the next batch.

• Uniformity Check: All 12 should look identical. Compare their appearance and weight. If one rod appears different, you may have had a contact issue on that rod – this needs addressing before the next run.

• Document the Process: Write down the exact parameters used: solution type and volume, current (or voltage) and time, temperature, agitation method. This recipe should be followed by other labs. Encourage each lab to replicate these conditions as closely as possible. For instance: “Plated 12 electrodes simultaneously at 5 mA/cm² for 30 min at ~25 °C in 500 mL of Spa Plating solution, using a Pt mesh anode encircling the cathodes.” Such details help others match your process.

• Batching vs Sequential: If a lab lacks the ability to do all 12 at once (maybe their power supply can’t source enough current or they only have a small beaker), it’s acceptable to plate in two or three batches. In that case, it’s vital to keep conditions constant:

  • Use the same solution (or same volume replenished to original concentration) for each batch.
  • Plate each batch for the same time and current density.
  • Perhaps swap the order of rods (don’t always put the same subset in the first batch) in case there’s slight solution depletion over batches.

  But ideally, design the plating setup so even small labs can do one batch. For example, plating 6 at a time (two batches) is workable – still, all 6 in a batch should be uniform, and you’d compare batch1 vs batch2 by weight to ensure consistency.

7.4. Cross-Lab Consistency:

• Once Lab A produces 12 electrodes, Lab B in another location should attempt the same protocol. They should compare notes: e.g., weights of their electrodes, visual appearance, any differences. Minor discrepancies can be ironed out (maybe Lab B’s power supply was uncalibrated, giving slightly lower current – they might increase plating time by 2 min to compensate).

• It might be wise for one lab to send a couple of electrodes to another as references. Alternatively, all labs send one electrode to a central facility for thickness measurement (via XRF or SEM). This external validation can certify that “all labs achieved ~2.5 µm ±0.2 µm plating” – boosting confidence in experimental data obtained with those electrodes.

• In the AMYBO context, the community’s collaboration (as seen with sharing designs and Spa Plating’s input (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org)) is valuable. If one lab perfects the plating procedure, they should share any tips or slight modifications needed. Over a few iterations, a robust standard operating procedure (SOP) for making 12 matched electrodes will emerge.

By following the above method, you can reliably produce a dozen platinum-plated Ti electrodes that are virtually identical. These can then be distributed to different research groups, used in parallel experiments, or kept as spares – all with confidence that each electrode is equivalently manufactured. This level of consistency is crucial for academic trials comparing results across different locations.

8. Producing 2 Matched Electrodes Using an ElectroPioreactor

For small-scale needs – say you want to make just a pair of electrodes for a pilot experiment or to test the feasibility – you might consider using the ElectroPioreactor itself as a mini-plating setup to save cost. This section outlines a cost-effective methodology for plating a pair of electrodes and assesses using the electroPioreactor versus a bench supply in this scenario.

8.1. Setup for 1–2 Electrodes in the ElectroPioreactor:

• Using the Pioreactor Vessel: Leverage the 20 mL vial and cap designed for electrolysis. The community has a vial cap design with a hole for a 6 mm electrode (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org), which is perfect for holding your titanium rod. Print or obtain this cap, and mount the titanium rod (to be plated) through it so that ~35 mm extends into the vial. For the counter electrode, you can use a small platinized titanium mesh or the second titanium rod (though if the second rod is also to be plated, you’d have to configure a way to plate one as cathode and use another as temporary anode, then swap).

• Wiring: Connect the rod to the Pioreactor’s LED driver channel (for instance, channel D positive to the rod for cathode, and channel D negative to the counter electrode if the Pioreactor is sourcing current in that configuration as it did for electrolysis (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org) – note, previously they connected platinized electrode to positive and SS to negative to generate hydrogen (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org); for plating, the titanium rod must be the cathode (negative) so it receives platinum). You may need to invert connections: titanium rod on negative, platinum mesh on positive of channel D.

• Plating Solution in Vial: Fill the vial with a small volume of platinum plating solution. 20 mL might be sufficient for a thin plating on one rod. Since volume is small, platinum concentration will deplete faster – consider using the highest concentration solution available or replenishing after one electrode. Alternatively, if you can get a slightly larger container (maybe a 50 mL tube) that still fits in the Pioreactor heater/stir base, that could allow ~30–40 mL solution.

• Parameters: Set the Pioreactor to drive current. For example, start with a low LED intensity (e.g. 10–20%) as per the earlier electrolysis tests (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org). You might need to determine empirically what current that corresponds to. One approach: connect a multimeter (in series or use a shunt resistor) to measure the actual current at a given setting (e.g. 10% gave X mA). Suppose 10% intensity yields ~10 mA through the electrode pair – that might be ~1.5 mA/cm² for a 6.59 cm² area (very low). You may increase intensity to max (100%) if needed. If 100% corresponds to, say, 50 mA (this is hypothetical), that would be ~7.6 mA/cm² – which might plate slowly but at least reasonably.

• Plating Procedure with Pioreactor:

  1. Clean and etch the titanium rod as in Section 5 (do this outside the Pioreactor).
  2. Insert it into the cap/vial with plating solution. Insert the anode (mesh) as well – maybe attach it to another port on the cap or dangle it in solution without touching the Ti rod.
  3. Start the current via Pioreactor software. Let it run for an extended time – possibly several hours. Monitor occasionally for any signs of problems (excessive bubbling, which could raise pH or cause non-uniformity in such a tiny volume – if so, you might dial down the intensity intermittently).
  4. After the time, stop and rinse the rod.

• Swap and Repeat: Plate the second rod in the same manner. (If you used the second rod as an anode initially, that rod will not really receive Pt – it might get slight oxidation. Clean it and then plate it as cathode with the first rod or mesh as anode.) Because conditions in the Pioreactor are limited, try to ensure the total charge passed (current × time) is the same for both rods. For instance, if you ran 10 mA for 4 hours (~144 C of charge) for rod 1, do the same for rod 2. This should give comparable thickness.

8.2. Bench Supply vs. Pioreactor for 2 Electrodes:

• Feasibility: It is feasible to use the Pioreactor alone, as demonstrated by the team’s electrolysis experiments. The Pioreactor effectively acted as a low-current power source (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org). For plating 2 small electrodes, this can work – albeit slowly. The advantage is cost: you avoid buying a bench supply, using the hardware you already have.

• Drawbacks to consider:

  • Time: Plating could take a long time due to low current. If the Pioreactor can only supply, say, 10 mA, depositing 0.035 g Pt might take on the order of tens of hours (depending on efficiency). This ties up the device and requires patience.
  • Monitoring: The Pioreactor’s software isn’t built to measure plating current or automatically stop at a certain point, so you have to approximate or manually time it.
  • Solution Volume: 20 mL is a very small bath. The local platinum ion concentration near the cathode may drop during plating, risking a rough or non-uniform coat. Agitation is limited in the tiny vial (though bubble stirring from gas evolution might help a bit). If possible, stirring with a small magnetic flea in the vial (if the Pioreactor has a stirrer) or manually swirling occasionally will improve uniformity.
  • Quality: There is some risk the deposit might be less adherent or uniform compared to a proper setup. However, if all you need is a functional platinized surface and you’re willing to potentially re-plate or accept a slightly thinner coating, this method can be acceptable.

• Bench Power (even for 2 electrodes): If a bench supply is available (or can be borrowed), you could still use the Pioreactor vial as the container, but drive the plating with the bench supply. This hybrid approach might be best:

  • You’d still benefit from the small volume (less solution used) and convenient electrode holding of the Pioreactor setup, but get more control with the supply. For instance, set 20 mA on the bench supply and plate for a calculated time to get ~2 µm.
  • This way, you reduce plating time and have a clearer idea of the deposition. The Pioreactor itself can be turned off or just used to hold the vial (ensuring the Raspberry Pi isn’t sourcing the current).
  • Using the bench supply also avoids any chance of damaging the Pioreactor electronics if something draws more current than expected.

• Cost Analysis: If truly avoiding extra cost is crucial, the Pioreactor-only method saves ~£60–£100 (cost of a PSU). All other materials (plating solution, etc.) you’d need regardless. But consider the value of your time: a bench supply might plate an electrode in 30 minutes that would otherwise take 5+ hours on the Pioreactor. For two electrodes, maybe that’s manageable; for larger numbers it’s not. If many labs are going to do this, likely at least one bench supply per lab is a good investment (often labs have one already for general use).

8.3. Procedure Recap for 2 Electrodes (Pioreactor method):

1. Clean/etch both rods (maybe etch them together in the same bath).
2. First rod plating: Setup in Pioreactor vial with Pt solution and inert anode. Run Pioreactor channel at highest safe setting for a fixed time (record this).
3. Second rod plating: Repeat with identical setting/time.
4. Rinse and test both rods. They should have a visible Pt coating. Perform a simple check (weight or appearance). If one looks thinner, you might give it another session in the plating bath (with fresh solution if the first run exhausted it).

8.4. Outcome and Use:

• The two electrodes produced should be comparable to each other. They might have a slightly thinner platinum layer than the “ideal” 2.5 µm if time/current were limited. If they function well in initial tests (e.g. they produce no discoloration and remain stable during electrolysis, like the short platinum electrode in the forum test which maintained clear solution (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org) (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org)), then the method is a success.
• If problems are encountered (e.g. plating flakes off), you may need to resort to a bench supply or improve surface prep. Often, inadequate current can cause poor adhesion because the initial nucleation (“strike”) might not have been strong – one trick is to give a very short burst at a higher current (if possible) at the start to help nucleate Pt, then lower it. The Pioreactor might not allow a “burst” easily unless you manually swap to a bench supply briefly for a strike.

8.5. Conclusion on Small-Scale Method:
Using the ElectroPioreactor to plate a couple of electrodes is feasible and cost-effective, but it comes with trade-offs in time and possibly plating quality. It’s a clever use of existing equipment for a one-off or pilot run. However, for reproducibility across labs, if each lab tries to do this with their Pioreactor, slight differences in how the Pioreactor outputs current could introduce variability. Therefore:

• If the goal is absolute consistency across the world, it might still be better for each lab to use a standard power supply method.
• If the goal is to enable even resource-limited labs to create functional electrodes, then the Pioreactor method is valuable – just advise them on careful execution.

In summary, for two matched electrodes, one can successfully use the ElectroPioreactor as a micro-plating setup, but must be attentive to detail and possibly accept a longer process. Whenever possible, verify the end results (by weight or performance) to ensure those two electrodes meet the criteria. This approach underscores the flexibility of the Pioreactor system but also highlights why dedicated plating hardware is recommended for larger-scale standardization efforts.

---

References:

(Evaluating platinized electrodes for electrolysis - Development - AMYBO.org), (Evaluating platinized electrodes for electrolysis - Development - AMYBO.org) – Gerrit’s experiment setup with Pioreactor for electrolysis (indicates Pioreactor channel usage).
(Evaluating platinized electrodes for electrolysis - Development - AMYBO.org) – Observation of cheap platinized electrode failing (importance of quality plating).
(Evaluating platinized electrodes for electrolysis - Development - AMYBO.org) – Martin suggesting electroplating titanium bolt anodes (need for plating process).
(Evaluating platinized electrodes for electrolysis - Development - AMYBO.org) – Spa Plating’s Richard providing custom electrodes and videos (expert endorsement of DIY plating).
(Microsoft Word - Surface World Article - Web Copy 27.03.07.doc) – Typical platinum thickness ~2.5 µm on titanium anodes.
(P52510 | Platinum Plating Solution) – Example platinum plating solution specs (4 g Pt/L, 0.2–20 µm range, high uniformity).
(Titanium platinum plating question | Gold Refining & Metal Extraction Forum) – Expert advice on titanium activation: detergent, HF or alternatives (ammonium bifluoride + sulfuric) to enable plating.
(Bench Power Supply - Amazon.co.uk) – Example bench power supply on Amazon (~£60, widely used).
(72-2540 - Single Output DC Bench Power Supply with RS232 … - CPC) – Example bench power supply spec/price from Farnell (~£89).
(Titanium, rod, 100mm, diameter | GF04311638-1EA) – Titanium rod 6 mm spec (Grade 2, 99.6% pure).
(uxcell 5Pcs GR5 Titanium Rod, Dia 6mm 0.23" Length 100mm 3.94 …) – Availability of small GR5 titanium rods pack (for DIY).
(How to Estimate Gold Content in Gold Plated Parts - A.G. Metals) – Formula linking surface area, thickness, density to plating mass (used for thickness calc).
(Plating Thickness Measurements - Applied Technical Services) – XRF is a nondestructive method for measuring coating thickness (suitable for Pt on Ti).

ENDS

[arlombardo]

2/18/2025

Summary:
The valve team was unable to begin testing as our 3D printers were out of service. As soon as they are back online, we will start force testing to ensure that the pinch valves can apply 10N, and the physical prototype meets design constraints and specifications.

The anode team has completed the nickel-nickel and graphite-graphite tests and are pictured below. The nickel had enough fallout that we believe that it is a non-viable solution due to its potential toxicity. The graphite test had some sediment, but we are hopeful that annealing the graphite prior to testing will lower the amount of fallout. We are going to test 316 stainless steel this week to determine if the orange fallout seen in last week’s photos were a product of the grade of bolts we were using. We are also looking into finding platinum plated titanium, but have run into sourcing issues (if anyone has any contacts, please let us know!). We are also looking into plating our own, but due to high costs, this will likely be a stretch goal.

Nickel:

Graphite:

[arlombardo]

2/25/2025 Summary:
Valve Team: There were some minor changes to one variation of the solenoid housing (pictured below). Using a force gauge, we are able to test the force applied by the spring, and have found that the springs we have are not enough to close the tubing (~14N). We will be ordering different springs this week. Additionally, the solenoids we are using require 12V and 3A for full power. We will obtain a high current power supply, but may need to discuss powering the solenoid valve further as the recommended amperage to the raspberry pi is no more than 2.5A.

Anode Team: Annealed graphite - annealed graphite test is complete (results pictured below) and there was much less falloff in the vial. There are some longevity concerns with respect to platinum plated titanium. We will be running longer tests to determine the lifetime of the annealed graphite anode and cathode. We are looking into ordering platinum plated titanium and will hopefully be able to test it in the next couple weeks.

[arlombardo]

3/11/2025
Summary:
As our solenoid is 12V 3A, we will be buying a 12V 5A barrel jack adapter for the 12V source of the Pioreactor such that it can properly control the solenoid. The anode team has gathered data resulting in the graph below where the error bars represent the variability of current measured by the potentiostat. The lower graphite tests could be due to our annealing process not being thorough enough, and we will work this week to check and improve these results. In addition, we have found that there is a large amount of rusting in the nickel tests. We will investigate if this is due to the reaction, the water, or the purity of nickel. In 2 weeks (following our spring break) we will begin testing our anodes with bacteria to ensure that the anodes do not make the water inhabitable (potential nickel toxicity).

[Martin]

Looking good. What do the lighter coloured bars mean?

[arlombardo]

The lighter colored bars are the calculated expected current. in the cases of nickel-nickel and nickel-stainless, running the experiment at 5V overloaded the potentiostat. Assuming all other variables are constant (distance between anode and cathode, ions in water, etc…), we can use Ohm’s law to find the ratio of current to voltage, and back out the expected current at 5V.

[arlombardo]

3/24/2025
Summary:
Not a lot of updates for this week as we were on spring break. We are working with the bio department to find the best way to reconstitute our bacteria. Currently, because of the timeline constraints, we will likely run two tests in parallel and then send whatever grows in the pioreactor for genetic sequencing to affirm that the bacteria did grow (and they were the only thing that grew). For future testing, the anode team has acquired platinum plated titanium and will have those results by next week. The valve team has obtained a high current power supply to power the solenoids so that we can begin testing springs.

[gerrit]

Very exciting! I’m looking forward to seeing the results.

[arlombardo]

4/1/2025
Summary
Logistics: Procedure for bacterial tests are linked below. Please feel free to give us feedback on the process. We are also considering DNA sequencing after testing to see what other bacteria grew in the solution.

Valve Team: Our solenoid cannot overcome the spring force at the maximum stroke length. By shortening the stroke length, the solenoid is able to overcome the spring force. We are now testing our springs to ensure they can close the tubing while the solenoid can open the valve. We have integrated the dovetail modular design into our solenoid holder (pictured below) and will continue iterating on this design to ensure stability and fit.

Anode Team: All potentiostat tests are set to be done on April 10th, We are currently testing nickel, new graphite (without fillers), platinum plated titanium, and stainless steel as the anode with platinum plated titanium or stainless steel as the cathode. We are starting our pioreactor tests and are set to complete them by April 24th. We will run all tests initially without bacteria to set an OD measurement baseline before running with bacteria.

Bacteria Testing Procedure

[Martin]

Hi August, this is looking good, although - having tried without success - I would strongly advise against multivitamins for trace nutrients. I can’t edit or comment on your google doc, so have sent you my comments via email. For other’s reference, I’d currently recommend starting by trying to replicate successful HOB enrichments in the literature. Ones we have found to date use Rabaey, Yu or SL-6 for their micronutrients, with various mesonutrients (similar, but not identical, to the ones you list in your google doc).

[arlombardo]

UPDATE: I have changed the permissions on the google doc such that anyone can comment. Please feel free to leave suggestions/concerns there or on the forum!

[Martin]

If you can get your hands on NaMoO4.2H2O and CuSO4.5H2O I think Yu’s sulphate makes more sense for in-culture electrolysis as SL-6 and Rabaey’s chlorides will turn to chlorine and may bleach your bugs and/or corrode your anode.

Compared with Rabaey (which has even more chlorides) your mesonutrients with Yu or SL-6 will need to include iron and calcium.

[gerrit]

@arlombardo Which strains will you be using? Depending on where you sourced them from, they may already have suggested cultivation conditions and culture medium specifications?

[arlombardo]

4/22/2025

Summary:

Bacteria testing update! We have made the trace element solution following the procedure from Yu. The other two media will be made tomorrow, and we will begin bacteria testing shortly after. We will test autotrophic and heterotrophic in parallel to ensure that our anodes and cathodes are the only independent variables.

Valve team is switching gears to increase force on the tubing. Videos (minutes with attachments linked below as I cannot upload videos) show that neither our solenoid design nor a medical grade solenoid were strong enough to stop CO2 flow, and we need a much higher force than anticipated. We will post initial designs here in the coming days, and please feel free to make comments/suggestions on them.

Anode team has completed the anode/cathode control tests. Additionally, the new graphite (without additives) performed comparatively to pencil lead, however, there was much more debris in solution. We will normalize our bacterial tests by subtracting the steady state optical density of the control anode/cathode tests, and will also, at the end of the 24 hours, turn off stirring and CO2 to see how the bacteria vs falloff settles in solution. This will allow us to visually judge how much debris vs. bacterial growth is in the solution.

All Liaison Meeting Minutes

[arlombardo]

Summary:

Logistics: This was the final liaison meeting for the HMC AMYBO Clinic team. We have had such a wonderful time on this project and are looking forward to what this community achieves in the future. As for final deadlines, our poster presentation is next week and will be posted here when finalized. As will our final presentation.

Bacteria Updates: We have run the nickel and stainless steel and graphite and stainless steel tests. Observational results were promising as there was very little metallic sediment in the vial. We are in the process of running the platinum platinum tests and will have those results soon. Once the data is analyzed, we will post it here.

Valve Team: The final prototype is being tested and will be uploaded to printables once it is complete. We will link the site here when it is uploaded, along with the bill of materials.

Anode Team: Our potentiostat test results are below. Some materials had such high current densities that, at a 5V applied, the potentiostat could note read the current. Therefore, assuming all other variables are constant, we can use the voltage law to calculate the 5V applied current out. We are not sure why nickel is so high in comparison to platinum. We suspect that it is due to a black substance that forms on the nickel during tests, which increases the current density. We do have some concern about this affecting optical density, and this will be recommended as part of future work.

material	height [mm]	diameter [mm]	surf area [mm^2]	current density	current density	current density	avg current density [mA/mm^2]	standard deviation	voltage	5V current density
nickel with nickel	11.110	4.000	152.179	0.092	0.119	0.120	0.110	0.016	3.500	0.157
nickel w SS	11.110	4.000	152.179	0.107		0.114	0.111	0.005	3.500	0.158
old graphite w graphite	10.700	5.000	187.710	0.077	0.003	0.002	0.027	0.043	4.000	0.034
old graphite w SS	17.400	5.000	292.954	0.042	0.028	0.023	0.031	0.010	4.000	0.039
new graphite w graphite	12.900	3.000	128.648	0.072	0.000	0.000	0.024	0.042	5.000	0.024
new graphite w SS	6.050	3.000	64.088	0.266	0.014	0.000	0.093	0.149	5.000	0.093
platinum w platinum	11.000	5.000	192.423	0.074		0.073	0.074	0.001	3.500	0.105

[Martin]

Congratulations team on completing your poster and presentation - well done. @arlombardo is there a way we could publish (or publicly link to) your final presentation video here? Also, given that our forum uses Markdown like the website, if each team (or individual) was to post their full final results (with links to design files, etc.) here. I can then easily upload them to openValve.org and amy.bo/Anode

[arlombardo]

Hi @Martin! As soon as I have access to the final presentation, I will see if I can link it publicly here. As for our final results, I will put together two documents tomorrow with all of our final results summarized that you can put on the forum. We are currently working solely on our final report, but as soon as that is completed I will get on that. Additionally, the CAD files for the valve and full BOM will be uploaded tomorrow!

[Martin]

Brilliant, thanks @arlombardo and sorry I assumed you had finished everything, forgetting about the final report. Please feel free to share a draft with us if you think it may benefit from extra eyes prior to submission. There’s no major rush from our end.

[arlombardo]

Hi @Martin!

I have not received the video of the final presentation yet. However, I have compiled all of our results into two zip files for your use and have emailed them to you (I cannot upload zip files here). This includes part files and a BOM for the valve. Additionally, I have attached a jpeg of our poster presentation, as I think it summarized our team’s work nicely. I have also attached a pdf of the poster in the email. The final report has been submitted and will be sent to you via Lorena soon.