Wearable Sensors Adapted to Extreme Environments Based on the Robust Ionogel Electrolytes with Dual Hydrogen Networks

ACS Appl Mater Interfaces. 2022 Mar 16;14(10):12713-12721. doi: 10.1021/acsami.2c01137. Epub 2022 Mar 1.

Abstract

Nonvolatile ionogels are promising soft electrolyte materials for flexible electronics, but it is challenging to fabricate stable electrolytes with mechanical robustness. Here, through rationally optimizing the chemical structure of polymer matrix and ionic liquids, the high-performance ionogel electrolytes with mechanical robustness and stability were fabricated. There are double hydrogen bonding networks in the as-prepared ionogel electrolytes, one of which exists between the polymer chains while the other one existing between the polymer chains and ionic liquid molecules. By adjusting the content of the ionic liquid and the ratio of the two hydrogen bonding networks, the prepared ionogel electrolytes exhibit tunable properties with an elasticity of 1.3-30 kPa, a stretchability of more than 1800%, a fracture energy of 125.8-548.3 KJ m-3, and a coordinated self-healing efficiency of 6.2-37.9% to satisfy the needs of different application scenarios. The assembled wearable sensors based on the high-performance ionogel electrolytes can be attached to a part of the human body, detecting various motions and body temperature. Benefiting from the nonvolatile and hydrophobic properties of the ionogel electrolytes, the wearable sensors can be operated under extreme environments including high/low temperature (-15-100 °C) and high humidity (100% relative humidity). It is believed that this work provides prospects for the application of wearable electronic devices.

Keywords: environmental stability; extreme environments; ionogel; mechanical performance; wearable sensor.