Scalable Manufacturing of Flexible Electronic Systems and Smart Textiles

The transition from conventional rigid and battery-based electronics into flexible and self-powered circuitry will pave the way toward future wearable technologies. Flexible electronics, when fabricated using low-cost materials and mass production technologies, will be able to augment the functionality of everyday items, enhancing the way humans interact with machines. Unfortunately, the manufacturing approaches commonly used to prototype and fabricate flexible electronics are often based on materials and processes appropriate for rigid electronics. Expanding the range of low-cost materials, scalable fabrication techniques, and lightweight and wireless powering strategies applicable to flexible electronics will be desirable to lower current manufacturing barriers.

Paper, due to its low cost, biodegradability, and availability 10¹² tons of cellulose are produced annually), has gained considerable attention as a substrate for the development of printable electronics. These paper-based devices are flexible and even foldable, facilitating their conformability to other objects, and their use in a variety of applications, from packaging to healthcare. Similarly, the ubiquitous use of textiles in daily life and the recent miniaturization of electronic systems fostered the development of a fast-growing interdisciplinary research field that aims to incorporate wearable electronics into garments. These electronic textiles—called "e-textiles"—have demonstrated to serve as convenient platforms for personalized medicine and human-machine interfacing.

Several energy harvesting and wireless power transfer approaches have been proposed as lightweight and flexible alternatives to power e-textiles and paper-based devices. Triboelectric nanogenerators (TENGs)—capable of converting user-device interaction into electrical outputs via contact electrification—have been explored as a battery-less strategy to power wearable devices. Wireless power transmission (WPT) using resonant inductive coupling has also demonstrated to be a promising strategy to continuously power e-textiles in closed environments without significantly increasing their rigidity or weight.

This PhD dissertation focuses on the development of new cost-effective and scalable methods to design and manufacture self-powered paper-based electronics and to transform conventional fabrics into e-textiles. The resulting low-cost flexible electronics and wearables are lightweight, insensitive to moisture, and compatible with large-scale production processes, serving as a foundation for the future development and commercialization of smart garments and paper-based electronics devices that do not depend on batteries for their use.