Woven Temperature and Humidity Sensors on Flexible Plastic Substrates for E-Textile Applications

TLDR

Printing techniques can be used to fabricate e‑textile devices on large‑area polymeric stripes, enabling applications that standard lithography cannot currently support. The paper presents a woven textile that incorporates temperature and humidity sensors fabricated on flexible plastic stripes. The authors fabricate the sensors by conventional photolithography and low‑cost inkjet printing, characterize and compare their performance, and integrate them into a woven fabric equipped with a mechanical support, read‑out electronics, and a PC interface. The sensors can be woven without damage, perform comparably across fabrication methods, and successfully integrate with electronics, indicating a viable path for printed electronics in textiles.

Abstract

In this paper, a woven textile containing temperature and humidity sensors realized on flexible, plastic stripes is presented. The authors introduce two different sensors fabrication techniques: the first one consists of a conventional photolithography patterning technique; the second one, namely inkjet-printing, is here presented as an effective, low-cost alternative. In both cases, we obtain temperature and humidity sensors that can be easily integrated within a fabric by using a conventional weaving machine. All the sensors are fully characterized and the performances obtained with the two different fabrication techniques are compared and discussed, pointing out advantages and drawbacks resulting from each fabrication technique. The bending tests performed on these sensors show that they can be successfully woven without being damaged. A demonstrator, consisting of a mechanical support for the e-textile, a read-out electronic circuit, and a graphical PC interface to monitor the acquisition of humidity and temperature values, is also presented and described. This paper opens an avenue for real integration between printed electronics and traditional textile technology and materials. Printing techniques may be successfully used for the fabrication of e-textile devices, paving the way for the production of large area polymeric stripes and thus enabling new applications that, at the moment, cannot be developed with the standard lithography methods.