Stretchable electronic systems for wearable and textile applications

Abstract

Assembly of electronic components on rigid and/or flexible printed circuit boards is today the customary way to fabricate electronic systems in stationary, mobile and automotive applications. On the other hand, many of the demands from emerging application fields like wearable and textile electronics cannot be met if with standard technologies. These fields have therefore become mayor drivers for the development of novel technologies. Among these 'stretchable electronics' have attracted much attention recently. Especially for textile applications the potential of the electronic system to comply with the body shape and movement will considerably improve the user comfort. In this paper we will present a cost effective technology for the realization of stretchable systems by common printed circuit board techniques like lamination, lithography, etching and micro via technology with polyurethane as a stretchable matrix/substrate material. Mastering of the adhesion between ma terials and the transitions region from stretchable to non-stretchable parts of the system are crucial for the mechanical performance and robustness. Technical approaches and the obtained results to tackle these issues will be presented. After a complete embedding of the components/interconnections the systems can be firmly attached to textile or non-woven cloth, which can be subsequently integrated into garments. The described process technology bears the potential for large scale roll to roll processing. Reliability aspects for stretchable electronic systems are so far not standardized and will be discussed briefly. Electrical and mechanical functionality of test vehicles subjected to multiple stretch and mild washing cycles will be presented. A functional electronic demonstrator with embedded passives, a micro controller, and LEDs which was realized with this technology will be shown

Conducting Polymer Nanowire Arrays for High Performance Supercapacitors

“…Nowadays, multifunctional portable electronic devices are being produced with rapid progress. [1d],45 However, the development of energy storage devices for these carry‐on devices is much slower compared with the electronic devices themselves. [4a],[41b],[41e],46 Even now, it remains a challenge to fabricate an energy storage device (such as supercapacitor) with the advantages of being light weight, flexible and having high performance.…”

“…Pushparaj et al reported flexible energy storage devices based on nanocomposite paper. [46d] Cellulose was disolved into room temperature ionic liquid (RTIL) 1‐butyl‐3‐methylimidazolium chloride ([bmIm][45d]) using microwave irradiation and then was infiltrated into the vertically aligned thin‐walled multiwalled nanotubes (MWCNT) to form a uniform film of cellulose and [bmIm],[45d] embedding the MWCNT. The as‐obtained nanocomposite paper, which combined all three components (electrode‐spacer‐electrolyte) and formed the basic building unit in the resulting devices, was peeled from the substrate for using in the supercapacitor or lithium ion battery.…”

Game-changing opportunities for wireless personal healthcare and lifestyle

“…One technological enabler is smart packaging using ultrathin flexible and even stretchable electronics ( Fig. 1.2.13) [29] and textile integration of electronics [30,31]. As this form-factor requirement puts the packaging technology very much on the forefront, system-package co-design is essential, especially in view of electromagnetic compatibility (such as battery-antenna-body coupling).…”

Flat inductors for human motion energy harvesting

“…It can be done using parts of apparels moving relatively one to another 19 . Integration can be done using technologies, which can create flexible and stretchable connections 21,25 , even some methods of ones used in textile industry can also be used in creation of connections, for example, embroidery. The latter is considered as most promising method for formation of resistive and inductive elements, connections etc., because it alters any textile in the least relevant way.…”