Triboelectric active pressure sensor with ultrabroad linearity range by femtosecond laser shaping based on electrons dynamics control

Abstract

Pressure sensor plays an extremely important role for the pulse monitoring, which has greatly demands of sensitivity and ultrabroad linearity sensing range. Here, we propose a active triboelectric pressure sensor with ultrabroad linearity range by femtosecond laser shaping gradient height microstructures for triboelectric layers. We fabricate microcolumn arrays with gradient height on polydimethylsiloxane (PDMS) surfaces using femtosecond laser spatial-temporal shaping technology to shape Gaussian beam into double-pulse Bessel beams, and supplementing it with wet etching and imprinting technology. Based on these fabricated PDMS layers, the effects of the microcolumns with different gradients on the linearity range of the sensor are systematically characterized. When the height difference of the microcolumns is 2 µm, the sensor can maintain a high linearity (R2 ≈ 0.99996) with a sensitivity of 0.304 V·kPa-1 even when the detection pressure range reaches 0–330 kPa, which increase the linearity range of the pressure measurements by 66 times than that with uniform height microcolumns. As practical applications of the proposed sensor, it is shown to sense weak airflow, generate high-stability Morse code signals, and enable the detection of pathological heart rates. These results highlight the potential applications of self-powered triboelectric pressure sensors for health monitoring and human machine interaction.