Design of a Tunable PDMS Force Delivery and Sensing Probe for Studying Mechanosensation

This paper presents the design and analysis of an innovative PDMS probe for investigating mechanotransduction and force generation by mechanosensory cells and organs. The low Young's modulus of PDMS together with a novel ring-spring probe design allow an easily tunable stiffness of 1-100 mN/m or larger. The probe design limits the fluid drag and allows settling times of 200 μs or less depending on the compliance of the probe. Moreover, the custom-tailored tip geometry of this device allows good coupling to a variety of sensory structures. The probe can be used as a force sensor or a force actuator using force-displacement calibration curves computed by the finite-element method (FEM). Finally, a FEM modal analysis for computing resonant frequencies confirmed that probe resonances are in the high kilohertz range, allowing use across the frequency range of most biological sensors.