Environment stable ionic organohydrogel as a self-powered integrated system for wearable electronics

Abstract

Intelligent flexible sensors with comfort and self-powered properties are primary in next-generation wearable electronics. Nevertheless, most of the current flexible sensors can’t work independently, but have to rely on external...

Mechanically Stable All Flexible Supercapacitors with Fracture and Fatigue Resistance under Harsh Temperatures

“…With applied displacement loading, a drastic stress concentration behavior was observed on the crack region of PP gel, which points to a more likely structural fracture. Comparably, as Young's modulus of the PANI can reach 1 GPa (much larger than that of PP gel), [ 45 ] most stress concentration merely existed at the PANI‐electrode layer. The rigid PANI chain enabled them effectively deflects and blunt the advancing crack tip, thus preventing crack propagation.…”

“…Electrical Output Measurement: The flexible sensor was fabricated in the previous work. [45] This sensor unit can be operated normally by a power supply of prepared all-flexible supercapacitors at a driving voltage of 1.0 V. The current signal of the sensing unit generated by sign language gestures was acquired by a digital source meter (Keithley 2450) and the resistance signal acquisition (DAQ,TruEbox-01RC) for multichannel sampling.…”

A highly resilient and ultra‐sensitive hydrogel for wearable sensors

“…Additionally, the sensitivity (gauge factor, GF) of most conductive hydrogels increased with the increment of tensile strain. Consequently, higher GF values were mainly achieved at larger strains 27–35,37,38 . In contrast, human skin could detect tiny variations in pressures, deformations and loads.…”

“…The triply reversible bridges (hydrogen bonds, crystalline regions, and coordination interactions) worked in tandem to achieve high resilience and fatigue resistance (94% recovery ratio after 100 cycles). Moreover, the synergy of immobile Al 3+ cation and free SO 4 2− anion endowed the obtained hydrogel with extraordinary sensitivity (a gauge factor = 13.9, at 0.2% strain), superior to most conductive hydrogels 27,29–38,55 . Therefore, it could precisely detect human motions such as finger bending, vocal cord vibration and even gentle finger touching, showing great potentials in artificial skins and wearable sensors.…”

“…To date, conductive hydrogels were mainly prepared by introducing conductive additives (electrolytes, conductive polymers, metals, and carbon materials) into the 3D network of hydrogels 23–29 . However, it is usually an eternal dilemma to simultaneously improve their mechanics and sensitivity due to the inherent exclusiveness 30–38 .…”