The electronic eye camera shown on the cover is a notable advance in optoelectronics. Even with the latest technologies it is difficult to produce a device to match the feats of imaging achieved by the human eye. Its hemispherical detector provides a wide field of view and low aberrations, using simple, single-component optics. Conventional optoelectronics materials exist only on the planar surfaces of rigid semiconductor wafers and cannot adopt spherical shapes. Now a multidisciplinary team based at the University of Illinois at Urbana-Champaign and Northwestern University, Evanston, has created an electronic eye-like camera based on single-crystalline silicon technology. Two novel fabrication steps make this possible. First, the optoelectronic circuits are ultra-thin in unusual, two-dimensionally compressible configurations; second, specially designed elastomeric elements transfer these planar layouts into hemispherical geometries. In addition to eye-like cameras, these strategies should make it possible to integrate planar device technologies onto the surfaces of complex curvilinear objects, for use in health monitoring devices, ‘smart’ prosthetics and elsewhere. [Letter p. 748; News & Views p. 703]
[Cover photo by Darren Stevenson]