Eggshell-inspired membrane—shell strategy for simultaneously improving the sensitivity and detection range of strain sensors

Abstract

The tradeoff between sensitivity and detection range (maximum and minimum stretchability) is a key limitation in strain sensors; to resolve this, we develop an efficient and novel strategy herein to fabricate a highly sensitive and stretchable strain sensor inspired by the membrane-shell structure of poultry eggs. The developed sensor comprises a soft and stretchable surface-grafting polypyrrole (s-PPy) film (acting as the membrane) and a brittle Au film (acting as the shell), wherein both films complement each other at the electrical and mechanical levels. Au forms cracks under strain contributing to its high sensitivity and low detection limit, and s-PPy can bridge Au cracks and increase stretchability which has not been used in strain sensors before. The surfacegrafting strategy not only enhances interface adhesion but also tunes the brittle property of native PPy to render it stretchable. Utilizing the synergetic effect of the membrane-shell complementary structure, the strain sensors achieve ultrahigh sensitivity (>10 7), large stretchability (100%), and an ultralow detection limit (0.1%), demonstrating significant progress in the field of strain sensors. The membrane-shell (Au/s-PPy)structured strain sensor can successfully detect finger motion, wrist rotation, airflow fluctuation, and voice vibration; these movements produce strain in the range of subtle to marked deformations. Results evidence the ultrahigh performance and bright application prospects of the developed strain sensors.

Polymer Electrolyte Dielectrics Enable Efficient Exciton-Polaron Quenching in Organic Semiconductors for Photostable Organic Transistors

“…Organic field-effect transistors (OFETs) have high potential in various applications including drive circuits, wearable electronics, and sensors, − but their commercialization process has long been limited by their weak environmental stability. In many application scenarios of OFETs, they are inevitably exposed to the light environment.…”

Crack-Based Core-Sheath Fiber Strain Sensors with an Ultralow Detection Limit and an Ultrawide Working Range

“…With the fast growth of wearable sensing devices, flexible strain sensors have received considerable interest and have shown substantive applications in various fields, such as human motion monitoring, − artificial intelligence robot, , and human–machine interaction. − As a vital component of strain sensors, resistive strain sensors have attracted extensive research interest because of their easy fabrication, fast response mechanism, and simple read-out systems. , From the perspective of human motion monitoring, to monitor both tiny changes (e.g., pulse and swallowing) and large strain changes (e.g., finger and joint movement) in the body, sensitivity and sensing range are two important parameters to be considered in the design of flexible resistive strain sensors. , However, there is always a trade-off between sensitivity and sensing range . High sensitivity stems from considerable structural change under a tiny change in strain.…”

“…11,12 However, there is always a trade-off between sensitivity and sensing range. 13 High sensitivity stems from considerable structural change under a tiny change in strain. In contrast, the wide sensing range requires the sensor to maintain a conductive path under large deformation.…”

Stress-deconcentrated ultrasensitive strain sensor with hydrogen-bonding-tuned fracture resilience for robust biomechanical monitoring

“…In order to effectively measure the subtle and dynamic mechanical signals, sensitivity becomes the crucial benchmark determining the function and accuracy of the strain sensors for medical scenarios. At present, crack-based resistive sensors have been widely fabricated to achieve high gauge factor (GF), which contributes to improvement of the sensitivity [17,18]. It is worth noting that resistor thermal noise, which is positively associated with resistance, also significantly influences the detection output [13,19].…”