Bioinspired, High-Sensitivity Mechanical Sensors Realized with Hexagonal Microcolumnar Arrays Coated with Ultrasonic-Sprayed Single-Walled Carbon Nanotubes

Abstract

The development of a flexible electronic skin (e-skin) highly sensitive to multimodal vibrations and a specialized sensing ability is of great interest for a plethora of applications, such as tactile sensors for robots, seismology, healthcare, and wearable electronics. Here, we present an e-skin design characterized by a bioinspired, microhexagonal structure coated with single-walled carbon nanotubes (SWCNTs) using an ultrasonic spray method. We have demonstrated the outstanding performances of the device in terms of the capability to detect both static and dynamic mechanical stimuli including pressure, shear displacement, and bending using the principles of piezoresistivity. Because of the hexagonal microcolumnar array, whose contact area changes according to the mechanical stimuli applied, the interlock-optimized geometry shows an enhanced sensitivity. This produces an improved ability to discriminate the different mechanical stimuli that might be applied. Moreover, we show that our e-skins can detect, discriminate, and monitor various intensities of different external and internal vibrations, which is a useful asset for various applications, such as seismology, smart phones, wearable human skins (voice monitoring), etc.

Micro‐Nano Processing of Active Layers in Flexible Tactile Sensors via Template Methods: A Review

“…Yet, it is quite limited to heighten the sensing performance of the tactile sensor only by changing the types of conductive filler and polymer matrix. To further improve the performance of the tactile sensor, the researchers introduced micro-nano structures including microsphere, [36] micropyamid, [67] and micropillar [68] in their sensing layer. The characteristics of local stress concentration, high compressibility, and easy change of contact area caused by the appearance of micro-nano structures, greatly boost the sensitivity and pressure detection range.…”

Self-Healing Materials for Electronics Applications

“…Flexible and wearable smart electronic devices have received a myriad of research interest because of their important applications in sports performance monitoring, healthcare diagnosis, human activity detection, and entertainment [ 203 , 204 , 205 , 206 , 207 , 208 , 209 , 210 ]. Nonetheless, sensors that respond to mechanical deformation that induces a change in the capacitance or resistance are certainly prone to microfissures or mechanical damage under repetitive deformation.…”

Bioinspired carbon nanotube-based materials

“…Moreover, numerous specific sensors (e.g. mechanical sensor, 151 wearable strain sensor, 152 temperature sensor, 153 airflow sensor, 154 etc.) were developed with the methods of drop casting, air spray, ultrasonic spray, hybrid hydrogel, thermal mismatch design, etc.…”