Photolithography Enables Mass Production of Microfluidic Chips

High-tech printing company Toppan has developed technology to manufacture glass microfluidic chips using photolithography. Mass production of microfluidic chips using the technology will make it possible to produce chips in larger volumes and at lower cost than those manufactured via current injection molding technology, which involves injecting polydimethylsiloxane (PDMS), a type of silicone resin, into a metal mold.

Prototype of Toppan’s microfluidic chip. Courtesy of Toppan.

Microfluidic chips manufactured by injection molding using PDMS are widely used for testing due to the material’s excellent biocompatibility and suitability for optical analysis. The low productivity for microfabrication when using PDMS and the high cost of liquid silicone as a raw material, however, drive up the cost of chips, presenting an obstacle to more widespread use.

To address this challenge, Toppan has developed technology for producing microfluidic chips by applying microfabrication technology based on photolithography techniques cultivated in the manufacture of LCD color filters.

Specifically, channels with a width of 10 µm to several millimeters and a depth of 1 to 50 µm are formed on photoresist that is coated onto a glass substrate. A cover with openings for injecting fluid samples or specimens is then applied over the cured photoresist. The resulting microfluidic chips exhibit properties equivalent or superior to those of PDMS chips, with the added advantage of larger production volume and reduced cost.