Experimental evaluation of force and amplification factor of three different variants of flexure based micro displacement amplification mechanism

Microelectromechanical System (MEMS) based complaint displacement amplification mechanism capable of producing different displacement amplification factors in three different configurations is designed and experimented. Microprobe system having an acupuncture needle and high-resolution camera has been used to measure displacements, forces and stiffness of the designed mechanism. Configuration 1 gives amplification factor 7.6 with natural frequency of 222.13 kHz. Configuration 2 amplifies displacement 16 times with natural frequency of 258.62 kHz. Amplification factor of 16.14 and natural frequency of 215.51 kHz is achieved with 3rd configuration. Modal analyses of all the three configurations of the mechanism match well with the experimental values. The mechanism is analytically modeled and simulated using Finite Element Method techniques and fabricated using commercially available fabrication process PolyMUMPs. Kinematic sensitivity and performance analysis of the proposed mechanism is carried out to predict the behavior of mechanism with respect to different geometric parameters. The results show that with increasing angle of flexure, amplification factor decreases, and it becomes constant at angles higher than 6° with increasing input displacement. It further shows a significant change in amplification factor with increasing length but after 600 μm the change in amplification factor becomes insignificant. Analyses results demonstrate the viability of mechanism as a displacement amplification mechanism. A good agreement is found between numerical and experimental results. This amplification mechanism can be used independently or integrated with any conventional actuation as well as sensing mechanism in a microsystem where amplified displacement is desired for improved sensitivity and performance.