Deployable 3D mesoscale structures through wafer fabrication, geometric frustration and bistable auxeticity

TL;DR

This paper presents a wafer-based fabrication method for transforming 2D mesoscale devices into complex 3D structures with precise control, enabling advanced flexible electronics and optical devices.

Contribution

A novel wafer-compatible process that uses bistable microstructures and geometric frustration to create deployable 3D mesoscale architectures from 2D precursors.

Findings

Successfully fabricated 3D structures with sub-millimeter accuracy

Achieved complex shapes including curved surfaces and tunable-focus mirrors

Demonstrated shape retention after deformation

Abstract

Transforming planar mesoscale devices into precise 3-D architectures is vital for next-generation flexible electronics, implants, and adaptive optics, yet wafer-based manufacturing to free-standing 3-D structures remain elusive. We fabricate polyimide architected 2-D precursors whose bistable unit cells deploy into stable 3-D mesoscale structures. Target Gaussian curvature is encoded by conformally flattening the desired mesh and locally tuning each cell so its second equilibrium matches the required scaling factor, aided by a computed library of isotropically expanding, bistable microstructures. The resulting heterogeneous tessellations uniquely morph into complex shapes. A flat disk deploys into a hemispherical dome with sub-millimeter accuracy and retains its shape after indentation. The same process yields positive- and negative-curvature geometries and tunable-focus paraboloidal mirrors whose reflected laser patterns coincide with geometric optics calculations. Our wafer-compatible, generative algorithm extends far beyond flexible substrates, enabling truly deployable, high-performance electronics and optical devices.