MADEONEARTH

Report from the world of backyard technology

Insect Inside

Garnet Hertz will never want or need to debug insect evaluates the distance it travels based on his mobile robot, because it’s controlled by a live the length of its unenhanced stride, it’s possible cockroach. Fastened into the three-wheeled vehicle that when its steps are greatly amplified — as they via velcro cemented to its back, the bug drives by are when it is placed in the robot — its ability to moving a ping-pong ball under its feet. The ball fits navigate will be impaired. into the workings of a Kensington trackball, turned The bug buggy’s CPU is a Giant Madagascan Hiss- 45 degrees so that its two axes correspond to ing Cockroach (Gromphadorhina portentosa). Hertz angled-left and angled-right, rather than horizontal has worked with the species before, and it’s well and vertical. The movements are then decoded and suited to such applications. Their size and strength amplified by transistors to drive left and right rear let them move relatively large objects, and their wheels, which turn in slightly to reflect the roach’s native forest-floor habitat makes them well suited steering direction. to being literally pressed into service. Working with

Power comes from twin 24-volt DC motors and a insects requires no animal ethics procedures or 24-volt battery. Meanwhile, four infrared proximity approvals, unlike with mammals, and anyway, if you sensors surround the front of the vehicle and switch mistreat G. portentosa, it will hiss loudly. Cockroach-on a row of LEDs that shine in the roach’s eyes es in general, meanwhile, carry a pile of personal when the vehicle approaches an object. Because and cultural associations. Everyone has had their cockroaches avoid light, this is intended to discour- own vivid experiences with the Kafkaesque insects, age the robot from bumping into things. But if the and this just adds to the fun.