Micro 3D Printing For Biomarker Detection

Researchers in China have used Projection Micro Stereolithography (PµSL) to improve the fabrication of micropillar array electrodes (µAEs) for the identification and detection of biomarkers. µAEs are often used for electrochemical detection due to their potential to be miniaturized. PµSL, a micro-precision 3D printing technology from Boston Micro Fabrication (BMF), enabled researchers to produce 3D printed molds for reduced fabrication costs and increased device sensitivity. The µAEs built using the micro 3D printed molds were able to detect biomarkers with 1.5 time larger sensitivity compared to a planar electrode.

Most µAEs are fabricated with traditional processes that are both expensive and time-consuming. Because they limit aspect ratio and pillar height, these lithographic processes also limit the development of low-cost and high-sensitivity microsensors. 3D electrodes with larger surface areas and higher pillars can support larger current densities, but researchers still need a way to produce them cost-effectively. PµSL technology can create master molds for these low-cost, high-sensitivity µAEs.

micro 3D printed mold of the µAE

Using a BMF P140 3D printer, the researchers in China printed a UV-curable polymer onto a glass slide, forming the positive master of each micropillar array. The height of the pillars was either 100 µm, 300 µm or 500 µm. For each master mold, a PDMS mixture was then cast, degassed, and baked overnight. Negative PDMS replicas were then peeled away from the master and used to mass-produce PDMS micropillar arrays using soft lithography. To provide electrical conductivity, gold films were applied.

The researchers described their efforts in a paper, “Development of micropillar array electrodes for highly sensitive detection of biomarkers”, that was published by The Royal Society of Chemistry.

Interested in learning more? Download the full paper here.