headerSearch form

Changing the World through Creative Research

Strain-insensitive intrinsically stretchable transistors and circuits

Journal
Nature Electronics
Date
2021.01.25
Abstract
Intrinsically stretchable electronics has recently been realized as a promising class of devices for electronics-human interfacing. This is primarily because of their ability to form intimate interfaces with human body, hence enabling precise monitoring of physiological signals without constraining movement. Indeed, recent breakthroughs in designing functional polymeric materials and fabrication of integrated devices have enabled a range of skin-conformable devices and circuits that can operate under substantial mechanical deformations. However, strains experienced by the devices invariably lead to perturbation of electrical characteristics. Even if the changes are mostly reversible, they complicate electronic design and may hinder high-fidelity signal collection and processing. Here, we introduce patterned strain-distribution which is readily incorporated into existing fabrication processes of high-density stretchable transistor arrays, through the patterning of a mechanically-heterogeneous elastomer layer as part of the transistor structure. Owing to the increased local stiffness, strains on the active regions of devices are effectively reduced, hence allowing unchanged device characteristics under stretching up to 100%. This all-elastomer based design process enables uncompromised state-of-the-art device density (340 transistors/cm2) while having a broad tunability of the balance between mechanical stability and device density per specific application requirements. Finally, this mechanical design process further allows fabrication of strain-insensitive circuit elements, such as NOR gates, ring oscillators and high-gain amplifiers. Our intrinsically stretchable amplifier was shown to enable stable monitoring of human electrophysiological signals.
Reference
Nat Electron (2021)
DOI
https://www.nature.com/articles/s41928-020-00525-1