On‐Demand Crack Formation on DNA Film via Organic Solvent‐Induced Dehydration

Crack is found on the soil when severe drought comes, which inspires the idea to rationalize patterning applications using dried deoxyribonucleic acid (DNA) film. DNA is one of the massively produced biomaterials in nature, showing the lyotropic liquid crystal (LC) phase in highly concentrated conditions. DNA nanostructures in the hydrated condition can be orientation controlled, which can be extended to make dryinginduced cracks. The controlled crack generation in oriented DNA films by inducing mechanical fracture through organic solvent-induced dehydration (OSID) using tetrahydrofuran (THF) is explored. The corresponding simulations show a strong correlation between the long axis of DNA due to the shrinkage during the dehydration and in the direction of crack propagation. The cracks are controlled by simple brushing and a 3D printing method. This facile way of aligning cracks will be used in potential patterning applications.