Rapid prototyping of piezoresistive MEMS sensors via a single-step laser carbonization and micromachining process

We have developed a rapid and low-cost single-step fabrication method for MEMS piezoresistive force sensors using laser carbonization and micromachining. The technique uses a CO₂ laser to pyrolyze a polyimide film and thereby create piezoresistive nano/micro porous carbon patterns. Subsequently, the same set up is used to define sensor structural geometry. Double-clamped cantilever force sensors created using this technique exhibit a linear (r²=0.9) response to applied force in the range of 0-0.54 N, with a response time of 5 s and a sensitivity of 31.717±3.767 Ω/N.