Low cost, disposable and wearable body warmer using RGO sheets coated on cloth substrate as heating element

Increase in customer demand for durable and functional fabric has been created an opportunity for nanomaterials to be integrated onto the textile substrates. We have fabricated a single step approach for electrically conductive textile for large scale production of reduced graphene oxide (RGO) nanosheets coated cotton cloth based films for heat generation application. It can be used as electro thermal wearable body warmer, in many industrial and laboratory applications. The RGO nanosheets aqueous dispersion was successfully prepared by solution mixing of RGO in N-Methyl-2-Pyrrolidone (NMP) using ultra sonication process. For the fabrication of RGO coated cotton cloth, the heating element film formation is carried out by dip coating method. The thickness of the heating element film is around 200 μm. As-prepared RGO nanosheets and RGO coated textile (cotton) cloth were characterized using XRD, FE-SEM techniques for their structural and surface morphology analysis. The RGO coated cotton cloth based electro thermal film annealed at 80μC temperature showed a good heating performance. Saturated temperature of around 52μC was attained when 40V is applied for 1 min to the fabricated device. It has been observed that, the power drawn by the device at 40 V was 480mW. The nanomaterials offer wide potential applications when integrated with garments that can be used to sense and respond to external parameters like electrical, optical and physiological signals. Importantly, the direct use of the aqueous dispersion of RGO in NMP opens up a new window for the next generation innovative wearable textile electronic devices. However, the field of nanotechnology, by considering the features of the textiles due to light weight, corrosion free, chemical stability for biomedical, automobile, flexible electronics for wearable technology etc. applications.

I. Introduction

In the past few decades, the Micro and Nano systems have been playing a key role for the development of miniaturized electronic devices in various fields [1]. Especially, the electrical conductive functionality of textiles have been attracted growing interest in numerous applications in many fields such as e-textiles, chemical sensing, health care, wearable electronics, military, biomedical, outdoor displays, heat retaining windows, other heating systems like carpets, automobile seats and dicing of aircrafts driveways etc., energy conversion and storage [2]–[9]. They have been also used as heating elements designed for creating functional materials for wide range of applications mainly, integrated communication devices, flexible electronics, flexible heaters and nanomaterials to garments for cloth designing. The concept of cloth gives a transformation of electronic technology through innovation in wearable technologies [3]. The conventional heating elements are known to have lower response time for temperature saturation and have limited stretchability or bendability [4].