A team from the University of Illinois has modified muscle cells to move in response to light, thanks to the rapidly expanding field of optogenetics. This could eventually result in “ bio- bots” useful for health or environmental applications. The algae genes are spliced with muscle tissue from mice to make it sensitive to blue light.

Already considered a breakthrough, researchers started with a 3D- printed hydrogel skeleton and looped a ring of the modified tissue around. They fired a flash intermittently making the muscles move and even “ exercise” it to become stronger.

Researchers initially used electrical signals to stimulate bio- bots. They later used light as the signals can adversely affect a biological setting and don’t allow for selective control. The school’s bioengineering head Rashid Bashir says, “ Light is a noninvasive way to control these machines. It gives flexibility in the design and motion”. The team strategically positioned the rubber-band like rings of muscle on the backbone and could make bio- bots that perform a variety of functions. “ We can have multiple legs and multiple rings. With the light, we can control which direction things move,” adds Bashir.

Researchers used thin tissues as it can more easily absorb light and nutrients. Previously, bots used thicker pieces of muscle. They used light to exercise the muscle daily to make it stronger and able to move farther when contracted.

The team is looking forward for the next step of designing different types of 3D- printed skeleton designs and use them as “building blocks” for larger bots. A grad student Ritu Raman says, “ People can now use this to build higher order systems.” Not too high order, though, please.