A microcantilever system with slider-crank actuation mechanism

•A new actuation principle has been developed for enhancing the tip deflection.•Analytical models of the actuator are studied to optimize amplification ratio and balanced force/stroke output.•The prototype is fabricated by standard lithographic processes, and an integrated sharp tip is easily machined by a hybrid wet/dry etching method.•The fabricated cantilever shows a 22 μm in-plane motion of actuators can drive the microcantilever to deflect up to 230 μm.•The microprobe is targeted at the potential application in the multifunctional analysis instrument.

A microcantilever system with new actuation principle is developed for enhancing the range of tip deflection. Differing from conventional springboard-like actuation principle, the proposed microcantilever system is based on a slider-crank mechanism. In this system, out-of-plane deflection of the microcantilever can be translated and amplified from in-plane motion of high-powered thermal actuators, which is located away from cantilever body to ensure both energetic driving force and good thermal isolation. Analytical models of both the microcantilever system and the electrothermal actuator are studied concerning the optimized geometry for desired amplification ratio and balanced force/displacement outputs. The prototype is fabricated by standard lithographic process, and an integrated sharp tip is easily machined by a hybrid wet/dry etching method. The fabricated cantilever is experimentally tested and shows that a 22 μm in-plane motion from actuators at an input electrical power of 1026 mW can drive the microcantilever to deflect up to 230 μm, demonstrating the expected actuation principle. The developed microcantilever system with integrated sharp tip shows the promise to work as a microprobe in the multifunctional analysis instrument.