Rapid patterning of slurry-like elastomer composites using a laser-cut tape

We present a cleanroom-free, simple and low-cost fabrication approach utilizing a laser-cut tape for rapidly patterning slurry-like elastomer composites. A conductive polydimethylsiloxane (PDMS) composite was chosen for demonstration in this paper due to its wide use of sensing and heating in many applications. Two fabrication schemes were developed: embedding in a PDMS matrix and relieving on a PDMS substrate. In both schemes, the patterns were first inscribed on adhesive tape using a CO2 laser. The patterned tape then served as a positive mask when spreading the conductive PDMS over it. The patterns were eventually transferred to a substrate after scraping the excessive composite with a razor blade and then removing the tape. The feature resolution of the technique was about 90-100 mu m primarily determined by the laser beam diameter, the translational speed and the power. The height of the patterned structures was associated with the thickness of the tape, which ranged from 76.1 +/- 4.3 mu m to 168.9 +/- 8.2 mu m in this study. A thicker structure can be achieved by stacking more adhesive tapes. For a practical demonstration, the conductive PDMS was patterned on a PDMS substrate serving as a heating element. The elastomeric microheater was successfully heated to 92 degrees C with a power of 210 +/- 12 mW applied