Pacinian Corpuscle-Inspired Strain Conversion Enables Ultrasensitive, Linear, and Broad-Range Piezoelectric Sensing...

High-fidelity wrist pulse acquisition, essential for the early diagnosis and precise management of cardiovascular diseases, requires tactile sensors with both ultrasensitive and linear electromechanical responses. Biological Pacinian corpuscles transduce mechanical stimuli into localized strain via concentric lamellar architecture, enabling subtle and dynamic perception of pressure fluctuations. Inspired by the working mode of Pacinian corpuscles, this work presents a piezoelectric tactile sensor featuring a multilayer grooved architecture that transduces external pressure into localized in-plane strain within the piezoelectric layer, effectively enhancing dipole alignment and charge separation. Finite element simulations and experimental results confirm that the grooved architecture contributes to strain concentration, giving rise to an ultrahigh sensitivity of 185 mV·kPa^{- 1} and linear electromechanical response up to 300 kPa and a power density of 806 µW·cm^{- 2}. The tactile sensor enables high-fidelity acquisition of multi-site pulse waveforms and accurate estimation of blood pressure, facilitating comprehensive cardiovascular assessment via heart rate variability and Poincare analysis. This bioinspired design offers an effective approach to overcoming the intrinsic limitations of piezoelectric materials and holds significant potential for developing high-performance piezoelectric sensors for continuous, noninvasive health monitoring.