Self-powered ionic sensors overcoming the limitation of ionic conductors as wearable sensing devices. (December 2020)

• Record Type: Journal Article
• Authors: Zhang, D.; Qiao, H.; Fan, W.; Zhang, K.; Xia, Y.; Sui, K.
• Is Part Of: Materials today physics. Volume 15(2020)
• Publication Date: 2020-12
• Subjects: Ionic hydrogel -- Strain sensor -- Self-powering -- Direct current -- Sensitivity; Materials science -- Periodicals; Physics -- Periodicals; Electronic journals; 530.41
• DOI: 10.1016/j.mtphys.2020.100246
• Languages: English
• ISSNs: 2542-5293

Abstract

Abstract: Ionic hydrogel-based sensors (I-sensors) enable a wide range of wearable applications. However, limited by the signal carriers (i.e., ions) of ionic hydrogels, the I-sensors cannot work stably under commonly used portable direct current (DC) power sources for wearable devices owing to inevitable variation of their chemical compositions. Here, we present a new strategy for designing high-performance self-powered ionic hydrogel-based sensors (SPI-sensors) for wearable applications by simply replacing the metal electrodes of I-sensors with the battery electrodes. The strategy can not only maintain a stable ion concentration within I-sensors due to the insertion/extraction of ions on two battery electrodes during the signal transmission but also endow the sensors with self-powering capacity. The as-prepared SPI-sensors show ultrahigh stability, ultrawide sensing range (~2000%), and high sensitivity, and can recognize an ultrasmall strain of 0.01%, which is superior to the existing I-sensors. This study first demonstrates the feasibility of accurately detecting the full-range human motions based on the internal resistance change of well-designed batteries, paving a new way for practical application of I-sensors. Graphical abstract: Image 1 Highlights: A new strategy for designing-self-powered ionic hydrogel-based sensors for wearable applications has been developed. The as-prepared self-powered sensors show ultrahigh stability, ultrawide sensing range, and high sensitivity. The study first demonstrates the feasibility of detecting the strain change based on internal resistance change of batteries.