Ultra-Wide Range, High Sensitivity Piezoresistive Sensor Based on Triple Periodic Minimum Surface Construction

Small. 2023 Sep;19(36):e2301378. doi: 10.1002/smll.202301378. Epub 2023 May 1.

Abstract

Flexible piezoresistive sensors with biological structures are widely exploited for high sensitivity and detection. However, the conventional bionic structure pressure sensors usually suffer from irreconcilable conflicts between high sensitivity and wide detection response range. Herein, a triple periodic minimum surface (TPMS) structure sensor is proposed based on parametric structural design and 3D printing techniques. Upon tailoring of the dedicated structural parameters, the resulting sensors exhibit superior compression durability, high sensitivity, and ultra-high detection range, that enabling it meets the needs of various scenes. As a model system, TPMS structure sensor with 40.5% porosity exhibits an ultra-high sensitivity (132 kPa-1 in 0-5.7 MPa), wide detection strain range (0-31.2%), high repeatability and durability (1000 cycles in 4.41 MPa, 10000 s in 1.32 MPa), and low detection limit (1% in 80 kPa). The stress/strain distributions have been identified using finite element analysis. Toward practical applications, the TPMS structural sensors can be applied to detect human activity and health monitoring (i.e., voice recognition, finger pressure, sitting, standing, walking, and falling down behaviors). The synergistic effects of MWCNTs and MXene conductive network also ensure the composite further being utilized for electromagnetic interference shielding applications.

Keywords: 3D printing; electromagnetic interference shielding; finite element analysis; piezoresistive sensors; triple periodic minimum surfaces.