Diatom Bio-Silica and Cellulose Nanofibril for Bio-Triboelectric Nanogenerators and Self-Powered Breath Monitoring Masks

Abstract

The application of biodegradable and biocompatible materials to triboelectric nanogenerators (TENGs) for harvesting energy from motions of the human body has been attracting significant research interest. Herein, we report diatom bio-silica as a biomaterial additive to enhance the output performance of cellulose nanofibril (CNF)-based TENGs. Diatom frustules (DFs), which are tribopositive bio-silica having hierarchically porous three-dimensional structures and high surface area, have hydrogen bonds with CNFs, resulting in enhanced electrondonating capability and a more roughened surface of the DF−CNF composite film. Hence, DFs were applied to form a tribopositive composite film with CNFs. The DF−CNF biocomposite film is mechanically strong, electron-rich, low-cost, and frictionally rough. The DF−CNF TENG showed an output voltage of 388 V and time-averaged power of 85.5 mW/m 2 in the contact−separation mode with an efficient contact area of 4.9 cm 2 , and the generated power was sufficient for instantaneous illumination of 102 lightemitting diodes. In addition, a cytotoxicity study and biocompatibility tests on rabbit skin suggested that the DF−CNF composite was biologically safe. Moreover, a practical application of the DF−CNF TENG was examined with a self-powered smart mask for human breathing monitoring. This study not only suggests high output performance of biomaterial-based TENGs but also presents the diverse advantages of the DFs in human body-related applications such as self-powered health monitoring masks, skin-attachable power generators, and tactile feedback systems.

Self‐powered technology based on nanogenerators for biomedical applications

“…Reproduced with permission. [ 108 ] Copyright 2021, American Chemical Society. (C) Self‐powered human breathing and temperature sensors based on wearable PyNG.…”

Self‐Powered Artificial Mechanoreceptor Based on Triboelectrification for a Neuromorphic Tactile System

“…Human breathing has been monitored as a useful indicator for real‐time health monitoring and for the early diagnosis of heart failure and sleep apnea. [ 39 , 40 ] Specifically, breath‐monitoring systems based on neural networks can be used to learn and recognize complex breathing patterns. [ 41 ] We implemented a fully hardware‐based breath‐monitoring system to demonstrate further applicability of the proposed artificial mechanoreceptor module to the healthcare industry.…”

Smart Face Mask Based on an Ultrathin Pressure Sensor for Wireless Monitoring of Breath Conditions

“…This is because the former can hold rich megascopic electric dipoles/monopoles and are easily deformed under a low‐pressure stimulus, resulting in excellent mechanical–electrical conversion efficiency. [ 22,29,31 ] For typical applications, electrostatic self‐powered pressure sensors have been used in previous studies for various purposes such as monitoring breath frequency/amplitude [ 11,38–41 ] or for developing breath‐driven human–machine interactive systems. [ 42,43 ]…”