Direct optical polymer patterning As a platform for electronic devices, polymeric materials offer the advantages of intrinsic flexibility and stretchability relative to hard material devices. However, unlike materials such as silicon, there are few tools for large-scale patterning of monolithic devices. Zheng et al. developed an optical lithography technique for the high-throughput fabrication of transistor circuitry on stretchable substrates. In this method, ultraviolet light is used to control the local solubility of the polymer, which makes it possible to fabricate transistors on the micrometer scale. These devices can be made with high yield and excellent uniformity without compromising their electronic and mechanical characteristics. Science , abh3551, this issue p. 88