In summary, we demonstrated a miniaturized, pronotum-mounted system consisting of a neural stimulator, muscular stimulators, a radio-equipped microcontroller and a microbattery capable of the continuous flight control of 1 gram / 2 cm and 8 gram / 6 cm beetles in free flight.
To our knowledge, this is one of the first reports on a reliable, neuro-stimulated flight control mechanism in insects. Although there have been prior reports on the influence of electrical stimulus of the brain on insect
flight, the mechanisms and microsystem presented here offer distinct advantage for the remote control and study of insect flight.
One of the major advantages of our method is that the stimulation method is surprisingly simple and robust, and it implicitly makes use of the beetle’s own flight control capabilities – the beetle powers its own flight and levels to the horizon; perturbations are applied whenever a heading or elevation change is required. The implant method described here suffers from variability in stimulus voltage from insect-to-insect; this is likely due to the coarse nature of the stimulator and the use of electrical potential as the controlled variable (as opposed to charge delivered).
Smaller footprint microfabricated electrodes should improve the first issue, as well as reduce the overall power consumption of each stimulus. Moreover, newer designs should likely use charge delivery (as opposed to voltage levels) from microcontroller-driven current sources to elicit responses.
The idea for remote-controlled insects derives from a 1990 science fiction novel by Thomas A. Easton:
"There's the brain, the spinal chord, the motor centers. A cable, here, from the controller to the interface plug... wires from that to the brain." She explained how the controller, a computer, translated movements of the tiller or control yoke and the throttle and brake pedals into electrical signals and routed them as appropriate to the jets or the genimal's motor centers, triggering the genimal's own nervous system into commanding its muscles to serve the driver. All the necessary programming was built into the hardware...
(Read more about the Roachster from Sparrowhawk)
The remote controlled cyborg insect idea had an interesting mention in the excellent new John Twelve Hawks book The Golden City; this shows you how these cyborg insects will be used in the near future.
Doyle swiveled in his chair, reached up to a shelf, and took down a clear plastic box that held a dragonfly clinging to a twig... The dragonfly had been turned into something called a HIMEMS... Ramirez and the others simply called them "robobugs."
...he opened the box, took out the twig and carefully placed the HIMEMS in the middle of a table. The hybrid dragonfly was a blue-eyed darner with a long body... and a tiny video lens.
Slowly the insect moved its two pairs of wings... Doyle tapped his finger on the table, and the startled insect flew away.
Doyle... activated the HIMEMS program on the computer. The first image on the monitor showed something dark, with a rough texture, and Doyle guessed that the dragonfly was resting on a tree branch. He attached a joystick to the computer and gently pushed the lever forward. The dragonfly responded like a toy airplane, taking off and heading east...
He had learned to control the hybrids. You couldn't direct precise movements, but you could send the dragonfly in a general direction and then make it stop and hover...
Philip K. Dick also deserves a mention for the commercial flies from his 1966 novel The Simulacra, and don't forget Jeff Noon's blurbflies from his 2000 novel Nymphomation.