Credit: Proc. Natl Acad. Sci. USA

Researchers have discovered how cockroaches can speed through gaps just millimetres high — and have used their findings to build a compressible robot.

Kaushik Jayaram and Robert Full at the University of California, Berkeley, observed American cockroaches (Periplaneta americana) as they squeezed through a series of crevices that decreased in height. The insects could maintain speeds of up to 60 centimetres per second after entering these tight areas, and only slowed when the ceiling height reached 4 millimetres — about one-third of the insects' free-standing height. They achieved their speed by using their legs and feet to push against friction between their bodies, the ceiling and the ground.

The cockroaches' mode of locomotion inspired the development of a soft-bodied robot (pictured left) that can compress its height by half (pictured right), allowing it to move through a tight space.

Proc. Natl Acad. Sci. USA http://doi.org/bch5 (2016)