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Abstract Wearable piezoresistive sensors are being developed as electronic skins (E‐skin) for broad applications in human physiological monitoring and soft robotics. Tactile sensors with sufficient sensitivities, durability, and large dynamic ranges are required to replicate this critical component of the somatosensory system. Multiple micro/nanostructures, materials, and sensing modalities have been reported to address this need. However, a trade‐off arises between device performance and device complexity. Inspired by the microstructure of the spinosum at the dermo epidermal junction in skin, a low‐cost, scalable, and high‐performance piezoresistive sensor is developed with high sensitivity (0.144 kPa‐1), extensive sensing range ( 0.1–15 kPa), fast response time (less than 150 ms), and excellent long‐term stability (over 1000 cycles). Furthermore, the piezoresistive functionality of the device is realized via a flexible transparent electrode (FTE) using a highly stable reduced graphene oxide self‐wrapped copper nanowire network. The developed nanowire‐based spinosum microstructured FTEs are amenable to wearable electronics applications.
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A Self‐Conformable Smart Skin with Sensing and Variable Stiffness Functions
Artificial smart skins that integrate sensing and adaptiveness present a novel platform in wearable electronics on epidermis or next‐generation robotics. Herein, a highly sensitive capacitive touch senor based on a self‐conformable bi‐stable electroactive polymer (BSEP) is developed. The device combines the properties of conformable polymers and touch sensors, which grants the sensor the ability to conform to the shape of various surfaces and in different working conditions. A spray‐coated silver nanowire (AgNW) is selected as the sensor electrode for high‐resolution patterning. The unique antenna‐shaped electrode pattern results in a capacitance change of 31% when in contact with ground at a baseline of 0.13 pF. The BSEP provides stiffness tunability via an embedded compliant heater. The heater combines interdigitated silver with carbon nanotubes delivering uniform and highly efficient heating to create a tunable device with stiffness between 100s of MPa and tens of kPa, providing a large working flexibility. The efficient resistive heater provides uniform and stable heating over an area of 40 by 40 mm with a rate of 48 °C min−1at an input voltage as low as 7 V. This research merges intelligent polymeric systems and thin film electronics advancing conformable, skin‐like functional electronics.
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- Award ID(s):
- 1700829
- PAR ID:
- 10114102
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Intelligent Systems
- Volume:
- 1
- Issue:
- 5
- ISSN:
- 2640-4567
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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