This article aims to review nature-inspired chemical sensors for enabling fast, relatively inexpensive, and minimally (or non-) invasive diagnostics and follow-up of the health conditions. It can be achieved via monitoring of biomarkers and volatile biomarkers, that are excreted from one or combination of body fluids (breath, sweat, saliva, urine, seminal fluid, nipple aspirate fluid, tears, stool, blood, interstitial fluid, and cerebrospinal fluid). The first part of the review gives an updated compilation of the biomarkers linked with specific sickness and/or sampling origin. The other part of the review provides a didactic examination of the concepts and approaches related to the emerging chemistries, sensing materials, and transduction techniques used for biomarker-based medical evaluations. The strengths and pitfalls of each approach are discussed and criticized. Future perspective with relation to the information and communication era is presented and discussed.

A new kind of triboelectric nanogenerator (TENG) is developed based on electrospun PVDF and nylon nanowires. This nanogenerator exhibits the remarkable characteristics of easy fabrication, low cost and high output. Its open-circuit voltage and short-circuit current density respectively reach up to 1163 V and 11.5 μA cm(-2) driven by the vibration with a triggering frequency of 5 Hz and an amplitude of 20 mm. The peak power density is 26.6 W m(-2). It directly powered a DC motor without an energy storage system for the first time. By harvesting energy from the environment using this TENG, a fully self-powered UVR detection device is developed to show the level of UVR directly without additional components.

Charge density is one of the most important parameters of triboelectric nanogenerators since it directly determines performance; unfortunately, it is largely restricted by the phenomenon of air breakdown. Here, we design a self-improving triboelectric nanogenerator with improved charge density. A maximum effective charge density of 490 μC m−2 is obtained, which is about two times higher than the highest reported charge density of a triboelectric nanogenerator that operates in an air environment. At the beginning of the working process, the charge accumulation speed is increased 5.8 times in comparison with a triboelectric nanogenerator that is incorporated into the self-improving device. The self-improving triboelectric nanogenerator overcomes the restriction of air breakdown and exhibits an increased effective charge density, which contributes to the improvement of the output performance, and the increase of charge accumulation speed will accelerate the increase of the output power at the start of operation.

No abstract