A Novel Ultra-Highly Stretchable Mxene-Doped Hydrogel for Stretch-Insensitive Low-Pass Filters

Abstract

AbstractMXene hydrogels have garnered significant attention in the field of flexible electronics owing to their exceptional mechanical and electrical properties. Although extensive research has been devoted to stimulus-responsive flexible electronics, the development of stimulus-insensitive systems is equally critical for expanding their practical applications. In this study, we engineered MXene-based double-network (DN) hydrogels by incorporating MXene, ethylene glycol (EG), and salt solutions. The resulting hydrogels demonstrated outstanding mechanical performance, achieving an elongation at break of up to 1210% and withstanding compressive deformations of 70% without irreversible damage. Furthermore, the hydrogels exhibited high electrical conductivity, reaching a maximum value of 1 S/m. The synergistic integration of mechanical robustness and electrical conductivity enabled the hydrogels to function as highly sensitive strain sensors, capable of detecting both small (1%–5%) and large (10%–50%) strains with a linear response. Leveraging these properties, we fabricated hydrogel-based resistors and capacitors through optimized component selection and structural design. These components were subsequently integrated into a hydrogel-based low-pass filter featuring a stretch-adjustable cut-off frequency, based on the classic RC filter circuit model. Remarkably, the filter maintained stretch-insensitive behavior under varying strains, demonstrating its potential for stable performance in dynamic environments. This work not only provides a novel strategy for designing stretch-insensitive flexible electronics but also offers valuable insights into their practical applications in next-generation devices.

Keywords: MXene, DN hydrogel, Stretch-insensitive, Flexible low-pass filter