Flexible Fiber Enables Chipless Wearables

Researchers at Donghue University and the National University of Singapore created a flexible electronic fiber that uses the human body as part of the circuit to enable textile-based electronics without the need for batteries or chips. Designed for scalable manufacture of comfortable fiber-based electronics, the technology has potential in a wide range of applications using sensing, computation, display, or communication, including “smart” clothing. Results were published in Science. 

Until now, textile electronics often relied on rigid silicon components that limited seamless integration, energy efficiency, and comfort. Chipless systems face digital logic challenges, given the lack of dynamic energy-switching carriers. The researchers propose a chipless body-coupled energy interaction mechanism for ambient electromagnetic energy harvesting and wireless signal transmission through a single fiber. The fiber eliminates the need for extra chips or batteries on the textiles. Since the electronic assemblies are merged in a miniature fiber, it allows for scalable fabrication and compatibility with modern weaving techniques. 

The soft, thin fiber, or i-fiber, consists of three layers: a core that triggers an electromagnetic field, a dielectric layer to store human body-coupled electromagnetic energy, and an optical layer that allows visualization of the electric field.  

The authors rigorously tested the textiles for durability and comfort, including washability, dyeability, stability against moisture and sweat, and breathability. They created garments with a textile-based touchpad and display that conveyed information through wireless illuminating patterns without an external power source, as well as a wireless haptic carpet that could sense and visualize the touch area.