Sheng Xu and Zheng Yan, both University of Illinois at Urbana-Champaign, Urbana, IL, USA, and colleagues have developed a simple technique for the microfabrication of complex geometric 3D structures. Finite element analysis of the mechanics makes it possible to design 2D patterns. These are then attached to a previously strained substrate at a number of points. Relaxing of the substrate causes the material to bend and buckle, leading to its 3D shape.
The technique allows creating previously inaccessible classes of 3D constructs in advanced materials, including device-grade silicon. It is expected to be useful in building biomedical devices, sensors, and electronics.
The pop-up assembly technique has many advantages over 3D printing: it is fast and inexpensive, it can be used to build many different structures at one time, utilize many different materials, including silicon, incorporate different materials into one hybrid structure, be used to build structures on both micro- and nano-levels down to a thickness of 100 nm, and produce a wide range of different geometries.
- Assembly of micro/nanomaterials into complex, three-dimensional architectures by compressive buckling,
S. Xu, Z. Yan, K.-I. Jang, W. Huang, H. Fu, J. Kim, Z. Wei, M. Flavin, J. McCracken, R. Wang, A. Badea, Y. Liu, D. Xiao, G. Zhou, J. Lee, H. U. Chung, H. Cheng, W. Ren, A. Banks, X. Li, U. Paik, R. G. Nuzzo, Y. Huang, Y. Zhang, J. A. Rogers,
Science 2015, 347, 154–159.