Highly stable flexible pressure sensors with a quasi-homogeneous composition and interlinked interfaces

Abstract

Electronic skins (e-skins) are devices that can respond to mechanical stimuli and enable robots to perceive their surroundings. A great challenge for existing e-skins is that they may easily fail under extreme mechanical conditions due to their multilayered architecture with mechanical mismatch and weak adhesion between the interlayers. Here we report a flexible pressure sensor with tough interfaces enabled by two strategies: quasi-homogeneous composition that ensures mechanical match of interlayers, and interlinked microconed interface that results in a high interfacial toughness of 390 J·m−2. The tough interface endows the sensor with exceptional signal stability determined by performing 100,000 cycles of rubbing, and fixing the sensor on a car tread and driving 2.6 km on an asphalt road. The topological interlinks can be further extended to soft robot-sensor integration, enabling a seamless interface between the sensor and robot for highly stable sensing performance during manipulation tasks under complicated mechanical conditions.

Morphological Engineering of Sensing Materials for Flexible Pressure Sensors and Artificial Intelligence Applications

“…Typically, the stability of pressure sensor mainly includes cyclic stability, storage stability and the stability toward anti-environmental interference. The cyclic stability is related to the compressive resilience of active materials [ 62 ] and the interfacial adhesion stability between electrode and sensing layer [ 81 ], while the storage stability of devices is usually concerned with the stability of active materials in the environment and the effect of encapsulation. There are many interferences in environment (e.g., dynamic temperature) affecting the sensing signals of the device, resulting in a diverse coupling results, and the accuracy of sensing.…”

“…The sensor with a uniform and conformal nano-coating film on the surface of the hydrophobic pyramid PDMS has more than 10,000 stable cycles [ 80 ]. Furthermore, as for the connection interface of active layer, Zhang et al designed and compared the stability of the sensor with and without connection interface [ 81 ]. The results show that the sensor with interlinked interface possesses a more stable and repeatable output electrical signal than the counterpart (Fig.…”

“…9 Pressure sensors with stable response. a Comparison of stable cycle performance of that with strong linked-interface and that with uninterlinked-interface [ 81 ]. Copyright (2022) The Authors.…”

“…Establish a strong connection between the sensing layers and the connection between the sensing layer and the electrode [ 81 ]…”

“…Copyright (2018) The Authors and (2019) Wiley–VCH. Performance: high sensitivity [ 75 ] (Copyright (2020) The Authors), broad working range [ 50 ] (Copyright (2019) Wiley–VCH), stable sensing [ 81 ] (Copyright (2022) The Authors), low hysteresis [ 84 ] (Copyright (2019) Wiley–VCH), high transparency [ 226 ] (Copyright (2016) Springer Nature), directional-selective sensing [ 227 ] (Copyright (2018) Wiley–VCH). Technique: self-assembly [ 26 ] (Copyright (2014) Wiley–VCH), patterning [ 116 ] (Copyright (2017) Wiley–VCH), auxiliary synthesis [ 119 ] (Copyright (2020) Wiley–VCH).…”