Electrode Manufacturing Techniques

Electrode Manufacturing Techniques

Almost every glucose test strip starts as a set of electrodes on a plastic base, and two families of methods make them: Thick Film (Screen Printing) and Thin Film (Laser Ablation). Screen printing is the older, cheaper route[1][2]. Laser ablation patterns a thin metal layer instead[3].

Screen Printing

• Screen printing presses conductive inks, such as carbon and silver, through a mesh screen onto the strip base.
• Because it works with low-cost plastics and conductive pastes, it suits mass production at low cost[1].
• It also has a long track record. Commercial screen-printed strips arrived in the 1980s, and a 2010 review found that most point-of-care glucose sensors relied on disposable screen-printed enzyme electrode strips[2].
• The trade-off is detail. Printed lines are coarser, with a resolution of about 100 µm, and the printed surface is rough at a microscopic scale.
• That roughness can add strip-to-strip signal variability.

Thin Film/Laser Ablation

• This method starts by sputtering a thin film of a noble metal, such as gold or palladium, onto the plastic base.
• A laser then removes metal to leave the electrode pattern. Laser ablation and optical lithography are the main ways to pattern metal electrodes such as gold, and both fit industrial-scale manufacturing[3].
• Metal films conduct better than carbon inks and give a smoother, more uniform surface than a printed layer (see our page on electrode material composition).
• Finer patterning makes room for precise electrode layouts and sub-microliter sample chambers. It also leaves space for extra electrodes, one route to multi-analyte strips.
• The cost sits in the equipment, which takes more capital than a screen-printing line.

Reagent Deposition and Assembly

• Reagent Deposition matters for both methods. A sensing layer holding the enzyme and an electron mediator sits on the working electrode, where it turns glucose into a current the meter can measure[1].
• Inkjet Printing is one of the printing methods used to batch-fabricate disposable electrochemical sensors[1]. Compared with coating a broad area, it places small, precise drops of reagent, which conserves expensive enzymes.
• Precise placement also keeps the amount of reagent consistent from strip to strip.
• Assembly ends by laminating layers over the electrodes. Here's what surprised us: the blood chamber is simply a gap cut into an adhesive spacer layer. A hydrophilic cover seals it, and capillary force pulls the blood in[1].
• That small chamber is why strips need so little blood (more on the physics in capillary action and sample volume). Among strips still sold as of October 2026, FDA decision summaries list a minimum sample of 0.3 µL for FreeStyle Lite[4] and 0.6 µL for Accu-Chek Guide[5].