Sensitive Wearable Temperature Sensor with Seamless Monolithic Integration

TLDR

Accurate temperature field measurement is critical for many scientific problems. The study aims to develop a highly sensitive, flexible temperature sensor using monolithic selective laser reductive sintering to advance soft robotics and healthcare systems. A novel monolithic laser‑induced reductive sintering scheme creates a seamless structure that integrates a metal electrode and metal‑oxide sensing channel from the same material at ambient pressure, avoiding complex heterogeneous fabrication steps. The resulting NTC thermistor‑based artificial skin achieves the highest temperature sensitivity reported for NTC thermistors, can be fabricated on heat‑sensitive polymer substrates, and successfully measures exhaled breath temperatures for early respiratory pathogen detection.

Abstract

Abstract Accurate temperature field measurement provides critical information in many scientific problems. Herein, a new paradigm for highly sensitive, flexible, negative temperature coefficient (NTC) thermistor‐based artificial skin is reported, with the highest temperature sensing ability reported to date among previously reported NTC thermistors. This artificial skin is achieved through the development of a novel monolithic laser‐induced reductive sintering scheme and unique monolithic structures. The unique seamless monolithic structure simultaneously integrates two different components (a metal electrode and metal oxide sensing channel) from the same material at ambient pressure, which cannot be achieved by conventional heterogeneous integration through multiple, complex steps of photolithography or vacuum deposition. In addition to superior performance, electronic skin with high temperature sensitivity can be fabricated on heat‐sensitive polymer substrates due to the low‐temperature requirements of the process. As a proof of concept, temperature‐sensitive artificial skin is tested with conformally attachable physiological temperature sensor arrays in the measurement of the temperatures of exhaled breath for the early detection of pathogenic progression in the respiratory system. The proposed highly sensitive flexible temperature sensor and monolithic selective laser reductive sintering are expected to greatly contribute to the development of essential components in various emerging research fields, including soft robotics and healthcare systems.