Biomimetic Ultraflexible Piezoresistive Flow Sensor Based on Graphene Nanosheets and PVA Hydrogel

Abstract

unmanned underwater robots, [3] sleep apnea treatment, [4] and other biomedical applications. [5] Among these, mimicking sensory hair cells that are ubiquitous in the creatures such as fish lateral line, crocodile body, locust's legs, mammalian vestibular system, and hearing system has attracted significant interest among many researchers. In nature, sensory hair cells work based on mechanical deflection induced by flow, vibration, acoustic vibration, and gravitational force, generating electrochemical signals and transmitting them to the brain. [6,7] The organs of balance (saccule, utricle, and semicircular canals) are filled with a fluid called the endolymph, which has a high concentration of potassium (K + ) ions and is low in sodium (Na + ) ions. When a linear or angular acceleration occurs, the ciliary tip links stretch or relax, depending on movement direction. In the case of the links stretching, the tip-links' channels are opened, allowing entry of particular cations (including potassium) into the cell, causing depolarization in the cell.

Cellulose Gel Mechanoreceptors – Principles, Applications and Prospects

“…Reproduced with permission. [ 212 ] Copyright 2022, Wiley‐VCH. f) Schematic illustration of driving simulation testing processes.…”

“…Auditory sensors require high sensitivity and low detection limit to accurately detect very low oscillatory flows. Therefore, surface nanostructures such as vertically grown graphene nanosheets on a hydrogel nanocomposite as a piezoresistive auditory sensor (Figure 7d) [ 212 ] and fluorinated ethylene propylene (FEP) assembled into a TENG auditory sensor [ 214 ] have been created to enhance the surface area and deformation for higher oscillation sensitivity. These auditory sensors as mimic human vestibular system and cochlea (Figure 7e) have been demonstrated to be qualified for sound‐triggered on‐off switching systems, antitheft systems and voice recognition systems, etc.…”

A tough, anticorrosive hydrogel consisting of bio-friendly resources for conductive and electromagnetic shielding materials

“…29,30 Additionally, some PVA macromolecular chains produce agglomerates, forming insoluble or even insoluble granular structures that hinder internal crosslinking configurations and affect the mechanical properties of hydrogels. 27,31,32 Polyethylene glycol (PEG) is a non-toxic and harmless polymer with small steric hindrance and active group hydroxyl (-OH) 33,34 at both ends. The introduction of PEG can better link the macromolecular chains of PVA, minimize the cross-linking error, facilitate the cross-linking of molecular chains, and improve the ability to resist external force stretching or compression.…”

Design and evaluation of perception reconstruction with sensor system for artificial anal sphincter based on vector similarity

“…Nowadays, micro and lightweight pressure sensing devices are of paramount importance for various applications, such as capsule robotics 10,11 aerospace 12,13 and artificial organs 14,15 . These kind pressure sensors are based on capacitance or piezoelectricity 16 .…”