Transparent and Stretchable Piezoresistive Strain Sensors with Buckled Indium Tin Oxide Film

Abstract

Owing to excellent performance and a simple mechanism, stretchable piezoresistive strain sensors have been applied to human skin for monitoring physical activities, physiological activities, etc. However, it is still a challenge to simultaneously realize highly sensitive and stretchable piezoresistive strain sensors with high optical transparency. This study reports a transparent and stretchable piezoresistive strain sensor with 2D surface buckling by fabricating ultrathin indium tin oxide (ITO) film on the biaxially pre-stretched polyacrylate (VHB) elastomer followed by pre-stretch releasing. To the authors' knowledge, semiconductors are applied for a stretchable piezoresistive strain sensor for the first time. Furthermore, this strain sensor exhibits a high sensitivity of 569, a high transparency of 88% and a high biaxial stretchability of 110% at the same time. This device demonstrates the good long-term stability over 500 stretching-relaxing cycles. The high sensitivity can be mainly attributed to the piezoresistive effect of the semiconductor where carrier mobility and the resulting resistivity can be significantly changed by the strain. The strain sensors attached to human skin are used to monitor many human motions such as chewing, swallowing, breathing, and walking. ITO-based strain sensors pave the way toward the development of highly stretchable and sensitive wearable electronics.

Strain-Sensor-In-Pixel Technology for Resolution-Sustainable Stretchable Displays

“…Hence, the ability to adjust the sensitivity of each strain sensor and interconnect area becomes important. However, most research efforts currently focus on enhancing either the sensitivity of strain-sensors or the stability of interconnects, instead of developing both simultaneously. ,,− Consequently, an advanced approach that facilitates the selective deposition of both components in a single process is required. This approach enables the precise fine-tuning of sensitivity in a thin film, thus effectively managing the responses of both strain sensors and interconnects to stretching in their respective desired directions.…”

Flexible resistive tactile pressure sensors

“…Pressure-sensitive flexible resistive sensors are firstly created using the piezoresistive effect of single-crystal silicon material. 34 The piezoresistive effect refers to the phenomenon where the lattice of a silicon crystal deforms when force is applied, causing charge carriers to scatter from one energy valley to another, which changes the carrier mobility, perturbing the average quantity of carriers both longitudinally and transversely, leading to the changes of silicon's resistivity (Fig. 2a).…”