An Electret/Hydrogel-Based Tactile Sensor Boosted by Micro-Patterned and Electrostatic Promoting Methods with Flexibility and Wide-Temperature Tolerance

Abstract

With the rising demand for wearable, multifunctional, and flexible electronics, plenty of efforts aiming at wearable devices have been devoted to designing sensors with greater efficiency, wide environment tolerance, and good sustainability. Herein, a thin film of double-network ionic hydrogel with a solution replacement treatment method is fabricated, which not only possesses excellent stretchability (>1100%) and good transparency (>80%), but also maintains a wide application temperature range (−10~40 °C). Moreover, the hydrogel membrane further acts as both the flexible electrode and a triboelectric layer, with a larger friction area achieved through a micro-structure pattern method. Combining this with a corona-charged fluorinated ethylene propylene (FEP) film, an electret/hydrogel-based tactile sensor (EHTS) is designed and fabricated. The output performance of the EHTS is effectively boosted by 156.3% through the hybrid of triboelectric and electrostatic effects, which achieves the open-circuit peak voltage of 12.5 V, short-circuit current of 0.5 μA, and considerable power of 4.3 μW respectively, with a mentionable size of 10 mm × 10 mm × 0.9 mm. The EHTS also demonstrates a stable output characteristic within a wide range of temperature tolerance from −10 to approximately 40 °C and can be further integrated into a mask for human breath monitoring, which could provide for a reliable healthcare service during the COVID-19 pandemic. In general, the EHTS shows excellent potential in the fields of healthcare devices and wearable electronics.

Biomedical Applications of Electrets: Recent Advance and Future Perspectives

“…The internal capacitance and injected charge density of the TENG were significantly increased by optimizing the dielectric permittivity of the composite, resulting in higher output power and lower impedance. Chen et al prepared a double-mesh ionic hydrogel film by solution displacement treatment [ 160 ]. The hydrogel film can act as a flexible electrode and triboelectric layer.…”

“…Reprinted with permission from Ref. [ 160 ]. Copyright 2021, copyright Multidisciplinary Digital Publishing Institute.…”

Object recognition by a heat-resistant core-sheath triboelectric nanogenerator sensor

“…3f). 20,[32][33][34][35][36][37] Then the I-TENGs were placed in a heating furnace and heated at different temperatures for various times. These sensors were then removed and tested at room temperature.…”

Editorial for the Special Issue on Smart Devices and Systems for Vibration Sensing and Energy Harvesting

“…This Special Issue focuses on state-of-the-art vibration sensing and energy harvesting technologies. After being carefully reviewed, 11 articles have been accepted for publication in this Special Issue [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ] that can be divided into three aspects: (i) new materials for vibration energy harvesting applications, (ii) design and fabrication of vibration energy harvesters (VEHs), and (iii) system-level integration and testing of VEHs.…”

“…Chen et al proposed a novel double-network ionic hydrogel and fluorinated ethylene propylene (FEP) electret-based tactile sensor. Combining with a corona-charged FEP film, the output performance of the sensor is significantly boosted by 156.3% through the hybrid of triboelectric and electrostatic effects [ 7 ].…”