Hollow MXene Sphere-Based Flexible E-Skin for Multiplex Tactile Detection

Abstract

Skin-like electronics that can provide comprehensively tactile sensing is required for applications such as soft robotics, health monitoring, medical treatment, and human−machine interfaces. In particular, the capacity to monitor the contact parameters such as the magnitude, direction, and contact location of external forces is crucial for skin-like tactile sensing devices. Herein, a flexible electronic skin which can measure and discriminate the contact parameters in real time is designed. It is fabricated by integrating the three-dimensional (3D) hollow MXene spheres/Ag NW hybrid nanocomposite-based embedded stretchable electrodes and T-ZnOw/PDMS film-based capacitive pressure sensors. To the best of our knowledge, it is the first stretchable electrode to utilize the 3D hollow MXene spheres with the essential characteristic, which can effectively avoid the drawbacks of stress concentration and shedding of the conductive layer. The strain-resistance module and the pressurecapacitance module show the excellent sensing performance in stability and response time, respectively. Moreover, a 6 × 6 sensor array is used as a demonstration to prove that it can realize the multiplex detection of random external force stimuli without mutual interference, illustrating its potential applications in biomimetic soft wearable devices, object recognition, and robotic manipulation.

A review related to MXene preparation and its sensor arrays of electronic skins

“…When a forward force was applied to the sensor, for example, more force was concentrated on cones 1 and 2, resulting in more deformation and higher voltage outputs than on cones 3 and 4. Zhao et al 129 fabricated a hollow MXene sphere-based flexible E-skin for multiplexed tactile sensing by an MXene-ink screen printing method. The symmetry of the strain–pressure sensor array's electrical response in X , Y , and Z can reflect the direction of the external stimulus, and the magnitude of the response value indicates position.…”

Silver Nanowire/Silver/Poly(dimethylsiloxane) as Strain Sensors for Motion Monitoring

“…Conductive fillers conclude metal materials (nanoparticles, − nanowires, ,− etc , carbon nanotubes, ,,, graphene oxide, etc. , ), new two-dimension materials (MXene), ,− and conductive polymers. − …”

Microwave-Welded and Photopolymer-Embedded Silver Nanowire Electrodes for Skin-like Supercapacitors

“…Additionally, the intense pulse light welding process is specialized for local junctions; hence, it is impossible to weld a sizeable area of AgNW film at one time. Furthermore, the skin-like electrode not only requires good mechanical robustness to ensure seamless integration with the human skin but also has to have excellent environmental stability to prevent the degradation of electrode performance caused by human sweating or environmental oxidation. − To this end, despite considerable effort devoted to improving the environmental stability by combining AgNWs with different two-dimensional materials (such as MXene and graphene), these reported methods are commonly complicated and even sacrifice the transmittance of AgNW films. − Therefore, there is an urgent need to develop an efficient, nondestructive, and facile strategy to realize a skin-like soft electrode, enabling the fabrication of next-generation skin-like supercapacitors.…”