Strip Manufacturing: Screen Printing vs. Laser Ablation

Strip Manufacturing: Screen Printing vs. Laser Ablation

Two methods come up again and again when you read about how glucose test strip electrodes are made. Screen printing pushes conductive ink through a patterned mesh and keeps the cost per strip low, while laser ablation starts with a thin metal film and removes everything that isn't electrode, which gives tighter control over electrode size [1]. Either way, the finished strip is a tiny electrical cell built on plastic.

Why electrode size matters

An electrochemical strip has a working electrode coated with an enzyme and an electron mediator, a chemical that carries electrons from the glucose reaction to the electrode [2]. Depending on the brand, the enzyme is glucose oxidase or one of several forms of glucose dehydrogenase [3]. When blood fills the chamber, the meter reads the electrical signal that reaction produces [3].

Strips have also shrunk. Lan and colleagues note that the blood sample a meter needs fell from 25 microliters to as little as 0.3 microliters over the decades [1] (more on that in our article on capillary action and sample volume). One Roche patent states the engineering consequence plainly: analyzing a smaller sample means making the strip's parts, electrodes included, as small as possible [4].

Screen printing: ink through a mesh

Screen printing is the same basic idea as printing a T-shirt. A conductive paste is pressed through a screen onto plastic sheets, and the sheets are then cut into strips. Wu and colleagues describe disposable test strips as made "by printing and cutting at a large scale using low-cost materials such as plastics and conductive pastes," and say screen-printed thin-film electrodes allow mass production at low cost [2]. Lan and colleagues credit screen printing with lowering the production cost of glucose test strips [1].

It is also the older method in this product. Yoo and Lee date commercial screen-printed strips for home glucose testing to the 1980s, and they write that most point-of-care glucose biosensors rely on disposable, screen-printed enzyme electrode strips [3]. A 2009 review of China's glucose sensor industry reports a meter with a screen-printed carbon sensor in commercial production there since 1994, and says mass production of screen-printed strips spread widely among local makers [5].

The inks are their own materials story. Carbon is one printed electrode material [5]. The reference electrode, the one the meter measures voltage against, is commonly made from a silver/silver chloride paste [6]. We got a sense of the scale from a 2012 paper by Nagarale, Hoss and Heller: it puts the number of silver/silver chloride reference electrodes made each year for glucose monitoring strips at about one billion [6].

Laser ablation: cutting electrodes out of metal

Laser ablation works in reverse. The maker starts with plastic already coated with a very thin metal layer, then uses a laser to remove metal until only the electrode pattern is left. Roche Diagnostics filed a patent on this approach for electrochemical sensor strips in 1999. In it, a laser ablates through part of a metal layer on an insulating base to form electrodes, and one of its figures shows the process with a gold film 50 nanometers thick [7]. A nanometer is a millionth of a millimeter.

A later Roche patent sets the methods side by side. It describes screen printing as a wet chemical technique that reliably forms gaps or features of about 75 micrometers or larger, and laser scribing as cutting individual lines with a high-power laser. Its own method, broad-field laser ablation, forms the entire electrode pattern at once, in nanoseconds, and its preferred electrode gaps include about 17 to 50 micrometers [4]. A third Roche patent claims electrode edges that stray less than about 6 micrometers from a straight line [8].

Keep in mind what these documents are. A patent records what a company claimed for its invention; it is not an independent test, and it doesn't tell you which products, if any, use the method.

Here's what surprised us: in Roche's 1999 patent the two methods aren't rivals at all. After the laser cuts the electrodes, the described process screen-prints a UV-curable dielectric, an insulating layer, onto the ribbon before the reagent goes on [7].

The trade-off in plain terms

Cost and scale favor screen printing, and both reviews we read tie it to low-cost mass production [1][2]. Precision favors laser ablation. It has been used to control electrode dimensions accurately in glucose strips [1], and Roche's patents claim smaller gaps and smoother edges than screen printing reliably gives [4][8].

Materials split along the same line. Screen-printed electrodes have to be made from a composition that is both conductive and printable [4]. The laser approach works on thin metal films; the Roche patent's list of candidate metals includes gold, palladium and platinum [4]. Our article on carbon paste vs. sputtered gold electrodes goes further into those materials.

What we couldn't confirm

We wanted to tell you which method is inside the strips you use, and we couldn't confirm it for any brand. As of October 2026, we had read the FDA 510(k) decision summaries for eight widely sold strip families. They cover the enzyme, the measuring principle and the accuracy studies, but none of them say how the electrodes are made. One describes its strip only as "a plastic strip containing chemicals and electrodes" [9].

So until a manufacturer says so in its labeling, calling a particular brand "laser-cut gold" or "printed carbon" is an educated guess. What those summaries do report is how each strip compared with a laboratory reference analyzer [9], and that is the part of strip quality you can actually look up.