The cyborgs are coming! US researchers reveal tiny robot that walks using a strip of lab-grown muscle cells



Robot can move by flexing skeletal muscle grafted onto it

Could lead to new generation of biological robots



It is the cyborg of the robot world, made up of both biological and mechanical parts.

Researchers have unveiled the first walking robot powered by live muscle.

The muscle is able to flex so the robot can propel itself across a lab - and researchers say it could lead to a new generation of flexible 'biobots'.

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The biobot is able to move when an electrical current is applied to a strip of skeletal muscle, causing it to contract.

HOW IT WORKS The design is inspired by the muscle-tendon-bone complex found in nature.

There is a backbone of 3-D printed hydrogel, strong enough to give the bio-bot structure but flexible enough to bend like a joint.

Two posts serve to anchor a strip of muscle to the backbone, like tendons attach muscle to bone, but the posts also act as feet for the bio-bot.

A bot’s speed can be controlled by adjusting the frequency of the electric pulses.

University of Illinois researchers developed the tiny muscle-powered 'bio-bots,' small biological machines that can be controlled with an electric current.

The walking 'bio-bots' are powered by muscle cells grown into a strip and controlled with electrical pulses, giving researchers unprecedented command over their function.



The group published its work in the online early edition of Proceedings of the National Academy of Science.



'Biological actuation driven by cells is a fundamental need for any kind of biological machine you want to build,' said study leader Rashid Bashir, Abel Bliss Professor and head of bioengineering at the U. of I.



'We’re trying to integrate these principles of engineering with biology in a way that can be used to design and develop biological machines and systems for environmental and medical applications.

'Biology is tremendously powerful, and if we can somehow learn to harness its advantages for useful applications, it could bring about a lot of great things.'



Bashir’s group has been a pioneer in designing and building bio-bots, less than a centimeter in size, made of flexible 3-D printed hydrogels and living cells.



Previously, the group demonstrated bio-bots that 'walk' on their own, powered by beating heart cells from rats.



Tiny walking 'bio-bots' are powered by muscle cells and controlled by an electric field. A bot¿s speed can be controlled by adjusting the frequency of the electric pulses.

However, heart cells constantly contract, denying researchers control over the bot’s motion.



This makes it difficult to use heart cells to engineer a bio-bot that can be turned on and off, sped up or slowed down.



The new bio-bots are powered by a strip of skeletal muscle cells that can be triggered by an electric pulse.



This gives the researchers a simple way to control the bio-bots and opens the possibilities for other forward design principles, so engineers can customize bio-bots for specific applications.



'Skeletal muscles cells are very attractive because you can pace them using external signals,' Bashir said.



'For example, you would use skeletal muscle when designing a device that you wanted to start functioning when it senses a chemical or when it received a certain signal.



'To us, it’s part of a design toolbox.



How it works: There is a backbone of 3-D printed hydrogel, strong enough to give the bio-bot structure but flexible enough to bend like a joint. Two posts serve to anchor a strip of muscle to the backbone, like tendons attach muscle to bone, but the posts also act as feet for the bio-bot.

'We want to have different options that could be used by engineers to design these things.'



The design is inspired by the muscle-tendon-bone complex found in nature.



There is a backbone of 3-D printed hydrogel, strong enough to give the bio-bot structure but flexible enough to bend like a joint.



Two posts serve to anchor a strip of muscle to the backbone, like tendons attach muscle to bone, but the posts also act as feet for the bio-bot.



A bot’s speed can be controlled by adjusting the frequency of the electric pulses.



'This work represents an important first step in the development and control of biological machines that can be stimulated, trained, or programmed to do work,' said graduate student Caroline Cvetkovic, co-first author of the paper.



'It's exciting to think that this system could eventually evolve into a generation of biological machines that could aid in drug delivery, surgical robotics, 'smart' implants, or mobile environmental analyzers, among countless other applications.'



Next, the researchers will work to gain even greater control over the bio-bots’ motion, like integrating neurons so the bio-bots can be steered in different directions with light or chemical gradients.



On the engineering side, they hope to design a hydrogel backbone that allows the bio-bot to move in different directions based on different signals.

