Introduction
Designing screen printed electrodes (SPEs) is not just a scientific task—it is a strategic engineering decision that directly affects performance, manufacturability, and cost at scale.
While many electrode designs begin in research environments, only a small proportion successfully transition into commercial products. The difference often lies in how early design decisions account for real-world manufacturing constraints.
This article brings together practical engineering insights into how to design SPEs that are not only functional, but scalable and commercially viable.
Start with Off-the-Shelf Electrodes First
Before embarking on a custom design or manufacturing programme, there is a strong practical recommendation:
💡 Start with off-the-shelf electrodes.
Using standard, commercially available SPEs allows you to:
- ✅ Validate your assay quickly
- ✅ Generate early experimental data
- ✅ Optimise electrochemical performance
- ✅ Reduce initial development risk
- ✅ Avoid premature design decisions
You can explore readily available, high-quality platforms here:
🔬 https://shop.zimmerpeacock.com/en-gb/collections/bare-electrodes
💡 Why this matters:
Moving too early into custom design often leads to redesign cycles, increased cost, and delays. Off-the-shelf electrodes provide a stable foundation for proof-of-concept before committing to scale.
What Makes a Screen Printed Electrode?
A typical SPE consists of several functional layers:
- Substrate – the base material
- Conductive inks – defining working, counter, and reference electrodes
- Insulating layer – controlling exposure and defining active areas
Each layer introduces both performance benefits and manufacturing complexity.
Substrate Selection: Choosing the Right Foundation
The substrate is effectively your manufacturing canvas.
Common Options
| Material | Advantages | Limitations |
|---|---|---|
| PET (Polyethylene Terephthalate) | ✅ Low cost, scalable, widely used | Limited thermal resistance |
| Polyimide | ✅ Flexible, ideal for wearables | Higher cost |
| Ceramic | ✅ High purity, excellent performance | Expensive, difficult to scale |
| PVC | ✅ Low cost | ❌ Stability concerns |
| Paper | ✅ Useful in microfluidics | ❌ Poor electrochemical reproducibility |
💡 Key Insight:
For most commercial applications, PET represents the lowest-risk and most scalable choice.
Ink Selection: Cost vs Performance Trade-Off
Material selection has a direct impact on both performance and cost.
Common Electrode Materials
- Carbon (Graphite) → scalable, low cost ✅
- Gold → high performance, expensive ❌
- Platinum → high performance, costly ❌
Cost Reality
- Gold can be ~179,000× more expensive than carbon
- Material choice alone can add €0.50 per electrode
💡 Design Principle:
If commercialisation is the goal, default to carbon unless a specific application demands otherwise.
Avoid Overengineering
A frequent mistake is directly translating laboratory setups into SPE designs:
Gold working + Platinum counter + Ag/AgCl reference
While scientifically valid, this creates:
- Multiple print steps
- Increased cost
- Lower manufacturing yield
Optimised Approach
- ✅ Carbon working electrode
- ✅ Carbon counter electrode
- ✅ Ag/AgCl reference and tracks (combined layer)
This simplifies production without significantly compromising performance.
Reference Electrodes: Rethinking Necessity
Not all applications require a true Ag/AgCl reference electrode.
Some commercial sensors use:
- Pseudo-reference systems
- Mediated electrochemical reactions
💡 Insight:
Removing Ag/AgCl can reduce cost and complexity—but must be validated carefully.
Insulation Strategy
Insulators define the active electrode area and protect conductive tracks.
However:
- They do not always need to be printed
- Alternatives such as laminated adhesive layers can serve the same role
💡 Example:
Commercial glucose strips often use layered tapes instead of printed insulators.
Electrode Size: The Hidden Lever of Cost
Electrode size is one of the most overlooked design variables.
Why It Matters
- Material usage scales with area
- Larger electrodes increase cost
- Fewer units per sheet reduce throughput
Practical Benchmark
- ~7.2 mm × ~26 mm = efficient, scalable format
💡 Key Insight:
Design electrodes to be as small as practical without compromising usability.
Standardisation: Use Proven Connector Designs
Using standard connector geometries improves compatibility.
Recommended parameters:
- Width: ~7.2 mm
- Pad width: ~1.5 mm
- Pitch: 2.54 mm
✅ Benefits include:
- Compatibility with existing potentiostats
- Faster integration into lab workflows
Sheet Format vs Singulation
One of the most important manufacturing considerations is how electrodes are handled.
Sheet Format (Recommended)
- ✅ Maintains order and traceability
- ✅ Enables automation
- ✅ Improves reproducibility
Singulated Electrodes (Avoid Early Use)
- ❌ Loss of positional data
- ❌ Increased handling error
- ❌ Inefficient for scaling
💡 Principle:
Stay in sheet format as long as possible, and only separate electrodes at the final stage.
Feature Size and Reproducibility
While micro-scale features are possible:
- <200–300 µm introduces variability
- Yield decreases significantly
Recommendation
- ✅ Design primarily at the millimetre scale
- ✅ Prioritise reproducibility over miniaturisation
Designing Beyond the Electrode
A commercial biosensor includes far more than the electrode:
- Functional coatings (enzymes, catalysts)
- Microfluidics
- Laminates and adhesives
- Electronics integration
💡 Perspective:
The electrode is only one component of a complete sensing system.
Practical Takeaways
📌 Start smart
- Begin with off-the-shelf electrodes
- Validate your assay before custom development
📌 Design for scale
- Use PET substrates
- Prefer carbon inks
📌 Simplify processes
- Reduce print layers
- Combine functions where possible
📌 Optimise geometry
- Avoid oversized electrodes
- Use standard connector formats
📌 Think manufacturing early
- Maintain sheet-based workflows
- Enable automation
📌 Prioritise reproducibility
- Stay within proven feature sizes
- Leverage experienced manufacturing partners
Closing Thoughts
Successful biosensor development depends not only on scientific innovation, but on disciplined engineering and manufacturing foresight.
By starting with proven platforms, optimising design decisions early, and aligning development with scalable processes, you significantly increase the probability of moving from concept to commercial product.
If you are exploring electrode design, assay development, or scaling strategies, engaging early with manufacturing expertise can help avoid costly redesigns.
👉 https://www.zimmerpeacock.com/contact
Hashtags
#Electrochemistry #Biosensors #PrintedElectronics #ScreenPrintedElectro
