kc7fys / CC BY SA 2.0

Monitoring how cockroaches recover from being shoved from the side could help engineers build sturdier robots.

The research into unbalanced cockroaches shows that the insects' central nervous system kicks in three times later than expected after the creatures are jostled, implying that other mechanisms are given priority when it comes to staying upright.

"What we see is that the animals' nervous system is working at a substantial delay," said Shai Revzen, an engineer and biologist at the University of Michigan, in a press release.

"It could potentially act a lot sooner, within about a thirtieth of a second, but instead, it kicks in after about a step and a half or two steps -- about a tenth of a second. For some reason, the nervous system is waiting and seeing how it shapes out."

The time delay points to the possibility that creatures knocked off their stride will only adjust their gait at whole step intervals, making for better stability and energy efficiency.

If you were curious as to how to study cockroaches tripping over, the researchers sent the insects running across a small bridge and onto a cart which promptly jerked to one side. According to Revzen, the force involved is roughly equivalent "to a sumo wrestler hitting a jogger with a flying tackle".

The movement of the roaches' feet and the ends of the body was then monitored using a high speed camera. Including data from a separate study monitoring nerve signals in the insects' legs allowed the researchers to see that the movement patterns only changed when the delayed action of the nervous system kicked in.

By using periodic (e.g. with each footfall) rather than continuous monitoring, engineers may be able to produce robots better able to cope with tricky terrain or bumps and knocks, although they suspect that adding more legs may also be of value: "Animals with eight or more legs might be more robust to lateral perturbations than hexapods." Essentially, spiders and scorpions might be even less likely to fall over than insects.

Also of interest is the potential of movement monitoring techniques to help understand human movement. "Falls are a primary cause for deterioration in the elderly," added Revzen. "Anything we can do to understand gait pathology and stabilisation of gait is very valuable."

The research was published in Biological Cybernetics online

Image: kc7fys / CC BY SA 2.0


Latest on wired.co.uk