Lateral nano-Newton force-sensing piezoresistive cantilever for microparticle handling

A lateral force-sensing piezoresistive cantilever is presented that can be used to evaluate the impact force between micro-handling tools and microparticles in the nano-Newton range. The 500 nm thick piezoresistive sensors are made from epitaxial silicon on single crystal silicon. The cantilevers are fabricated using bulk micromachining and are 300 mum long, 10 mum high and 14 mum wide. The applied force on this sensor is parallel to the wafer surface. This structure can eliminate the effect of the vertical force, increasing the sensitivity and accuracy of the system. The force resolution of the implemented sensor is 98 V N-1 with a minimum detectable force of 5 nN.