Background and Overview
With profound impact on personal electronics, energy, robotics, and healthcare, soft electronics technology has redefined not only the appearance, but also the design and fabrication of microelectronics. The search for pliable materials with superb electronic properties calls for strategies to bridge the gap between hard and soft – among which advanced engineering of the geometry and architecture of materials presents unique opportunities.
A prominent example of geometry engineering is that nanowires of hard and brittle piezoelectric oxides such as ZnO and PZT can be used as a flexible energy source. On the other hand, the 3D architecture of materials can be engineered by manipulating their 2D layout and the strain applied. For instance, the compressive straining of an elastic substrate can be used to fabricate previously inaccessible classes of 3D structures in monocrystalline materials. Conversely, rationally designed 2D geometries can buckle to form 3D layouts to accommodate tensile strain, resulting in unprecedented stretchability. This enables a series of device possibilities in stretchable electronics with mechanical properties similar to that of human skin.
The Xu group aims to understand the electrical, mechanical, and other characteristic behaviors of functional inorganic materials when they are geometrically engineered into a soft format, and explore these materials as building blocks for soft electronics, nano electronics, and energy harvesting/storage devices. In short: we make hard materials soft and use them to build electronics.