Digital cameras mimic visual prowess of bugs

A team of researchers from University of Illinois at Urbana-Champaign (UIUC) has developed what they claim as the first digital cameras with designs that replicate ocular systems found in dragonflies, bees, praying mantises and other insects. According to them, the technology offers wide-angle fields of view, with low aberrations, high acuity to motion and nearly infinite depth of field.

The cameras exploit large arrays of tiny focusing lenses and miniaturized detectors in hemispherical layouts, just like eyes found in arthropods. The devices combine soft, rubbery optics with high performance silicon electronics and detectors, using ideas first established in research on skin and brain monitoring systems by John A. Rogers, a Swanlund chair professor at UIUC, and his collaborators.

Eyes in arthropods use compound designs, in which arrays of smaller eyes act together to provide image perception. Each small eye, known as an ommatidium, consists of a corneal lens, a crystalline cone and a light sensitive organ at the base. The entire system is configured to provide exceptional properties in imaging, many of which lie beyond the reach of existing man-made cameras.

The researchers developed new ideas in materials and fabrication strategies allowing construction of artificial ommatidia in large, interconnected arrays in hemispherical layouts. Building such systems represents a daunting task, as all established camera technologies rely on bulk glass lenses and detectors constructed on the planar surfaces of silicon wafers which cannot be bent or flexed, much less formed into a hemispherical shape.

"A critical feature of our fly's eye cameras is that they incorporate integrated microlenses, photodetectors, and electronics on hemispherically curved surfaces," said Jianliang Xiao, an assistant professor of mechanical engineering at University of Colorado Boulder and coauthor of the study. "To realise this outcome, we used soft, rubbery optics bonded to detectors/electronics in mesh layouts that can be stretched and deformed, reversibly and without damage."