Credit: University of Illinois at Urbana-Campaign

Robots can be very strong, fast and enduring. However, unlike in animals, none of this strength comes from muscle, instead robots mainly rely on electrical motors and other hard and generally inflexible parts. But with all the advantages that conventional robot hardware can deliver, it still does not match the ability of muscle-powered animals to provide an accurate response to different physical environments. To address this downside of robotics, a group of researchers, led by Professor Rashid Bashir, at the University of Illinois at Urbana-Campaign developed tiny walking bio-robots powered by engineered muscle tissue.

The robot consists of a 6 mm long flexible 3D-printed backbone with two strains of muscle attached to each of its ends. The backbone has two little feet and is used both for walking and sustaining the structure. The important thing about the robot is that the muscle tissue used in it is the skeletal muscle, the one humans use to move around, which means that it can be easily turned on by administering electric impulses. Furthermore, by adjusting the frequency of the impulses, the robots’ speed can be modified.

The use of skeletal muscle allows for a better control over the robots’ movements. This significantly differs from the previous study conducted by the same group, where the researchers used heart tissue, which contracts non-stop and with a constant rate.

This technology is an important step on the way to integrating biological tissue in machines, which in some cases can be priceless. For example, muscle-powered robots are perfect for medical applications inside the body: the tissue is a perfect biodegradable material and such robots could run in a nutrient rich fluid without any additional power source. In addition, the use of muscle-powered limbs in biomimetic machine design would open hundreds of new possibilities, especially in the field of soft robotics. Imagine how much more lifelike a robotic starfish or octopus could be if powered by muscle tissue!

With the concept of a muscle-powered robot tested, the researchers are now preparing for the next step: the group envisions equipping their robots with light or chemically sensitive neurons for controlling direction of robot’s movement as well as testing new designs of the backbone to enable a wider range of motions.

The results of the study can found in PNAS in the article called “Three-dimensionally printed biological machines powered by skeletal muscle.”

Developed by researchers at Brigham and Women’s Hospital and Carnegie Mellon University, this pioneering technique combines recent advancements in tissue engineering, 3D printing and microrobotics. The scientists used magnetic fields to remotely enable these tiny robots – fashioned as a sort of microscale tweezers – to move one cell at a time, change its orientation and place it where needed with a precision and at a scale we previously thought to be unimaginable.

Credit: S. Tasoglu et al./Nature Communications

The study, published in Nature Communications, suggests that, unlike other existing bioprinting methods, this technique allows for precise modification of tissue architecture and is easily reversible. In other words, if before a misplacement of a cell-containing droplet could ruin the process in a blink of an eye, now a micro-robot can remove the misplaced droplet and place it where it belongs. This is the first time that cells are manipulated one by one in a 3D printing process with a full control of time and position.

Bioprinting and tissue engineering, for some time now, have been pushing the boundaries of our imagination by promising to bring about the possibility of creating new donor organs as well as devising new therapies and testing drugs using way more practical cell-based models. Thanks to micro-robots this possibility has just become one step closer.

Currently it takes a lot of time and money to produce, program and design a functioning robot. Although the project’s in its early phases, it aims to ¨dramatically reduce the development time for a variety of useful robots, opening the doors to potential applications in manufacturing, education, personalized healthcare, and even disaster relief,” explains Rob Wood, an associate professor at Harvard University.

On a larger scale, the project aims to democratize access to robots by advancing the state of the art of today’s increasingly accessible 3D printers- allowing individuals to design and build functional robots from material as readily available as a sheet of paper.

Researchers also envision that these types of robots could provide fix-it-yourself solutions for household problems;you could simply head to a printing store and pick out a blueprint from a catalog of robotic designs and customise an easy-to-use robotic device built to tackle the problem. Within a day, the robot would be printed, assembled, programmed and ready for use.

Can we make robots to help solve problems that are part of our daily lives? Click HERE to find out about a European initiative which envisions robots as companions for everyday citizens.