Fig. 4: Conceptual design, sensing mechanism (piezo-ionic dynamics), and sensing performance of MESHPIE-based device.

The design of MESHPIE-based device consists of MESHPIE sandwiched between two deformable AgNW/MESHE2 electrodes with voltages of 1 mV to 1 V. a At a pre-stimulus condition, ionic species are trapped to C–F groups (trapped state). b Under stimulus, MESHPIE exhibits ion pumping phenomenon owing to pressure-induced breaking of ion-dipole interactions. c Ion dynamics and free ion number concentration under increasing pressures. d Variation tendencies of charge relaxation time as a function of increasing applied pressures. e Impedance Nyquist plots of MESHPIE-based device for no pressure (NP), under pressure (UP), and after removing pressure (AP) conditions, strongly affirming the reversible ion movement. f Comparison of pressure sensitivities (100 mV applied bias at 20 Hz) of MESHPIE and NFPU-IL (insert, red) (used as a reference). g Pressure-dependent capacitance changes of MESHPIE as a function of applied pressures (0.04 kPa, 0.2 kPa, 1.5 kPa, and 10 kPa) with respect to time (100 mV applied bias at 100 Hz). h Transient response time at a loading pressure of 7.2 kPa (1 mV applied bias at 1000 Hz). i Mechanical durability test of the MESHPIE-based sensor device after self-healing in air and underwater (200 cycles each, 1 mV applied bias at 100 Hz).