Programmable Nanoscale Crack Lithography for Multiscale PMMA Patterns.

Crack lithography is important for preparing microstructured materials. This strategic use of cracking breaks with the traditional idea that cracks are unwanted and has great potential for high-resolution and high-throughput production. However, the ability to control nanoscale crack patterning is still insufficient. Here, we present a nanoscale, programmable angle-dependent technique to control crack generation that relies on standard electron-beam lithography. Multiscale patterns of poly(methyl methacrylate) of arbitrary shape, geometric size, and large area were obtained, greatly expanding the processing capacity of electron-beam lithography. In addition, we observed the interaction between adjacent structures and cracks, which resulted in crack suppression or second-order cracks. We also demonstrated that angle-dependent nanoscale cracks can be used in physical unclonable functions and have great application prospects in the field of information security. We believe that our strategy for programmable nanoscale crack patterning provides new opportunities and perspectives for nanofabrication.