Recent progress in wearable fully textile chemical sensors

In the new era of Internet of Things, there is a great demand for the development of novel chemical wearable sensors, in particular, for personalized medical diagnostics with point-of-care devices. This paper provides an overview on the recent developments in this field, focusing on fully textile chemical sensors, i.e., sensors directly incorporated into a garment/fabric/ fiber. The recent results are summarized by grouping them in three broad categories according to their working principle: (i) electrochemical sensors; (ii) transistor-based sensors; and (iii) resistance-based sensors. Wearable chemical sensors can be used to detect external dangerous vapor/agents, or to control and monitor the concentration of specific compounds in biofluids for safety and healthcare applications. One of the main issues of such applications is sensor operation in a complex medium containing many interfering compounds. To this end, recent novel approaches to enhance the selectivity of fully textile wearable sensors are reviewed: enzyme-based approach, selective membrane, and a potentiodynamic method. Finally, a critical overview is given about the major open issues that have to be overcome in order to reach a high technology readiness level.