Evaluation Platform for MEMS-Actuated 3D-Printed Compliant Structures

This paper presents experimental results on an evaluation platform for MEMS-actuated compliant structures. A combination of 3 dimensional (3D) flexure design, 3D printing of polymers with controlled stiffness is employed. A modular system design approach allows the interchange and combination of different actuation cantilevers, flexures and structure designs implemented as standalone test parts with minimal assembly requirements. The performance evaluation method includes synchronised electrical excitation and optical displacement measurements, allowing characterisation of motion amplification, dynamic response as well as actuating power transfer. As a demonstrator, a single lever compliant structure was designed, fabricated and tested on the platform to investigate how geometry and material stiffness affect performance. The experimental results reveal that significant improvement of amplification ratio and absolute phase lag can be achieved by selecting a flexure height and material composition suitable for a given application. This method of combined experimental evaluation and custom 3D design and printing is promising for optimising the design of compliant structures for MEMS sensors, actuators and energy transducers with amplified or translated motion capability.