Multi-directional artificial muscles demonstrate potential for creating flexible, agile robots.
Scientists at MIT have devised a novel approach to create articifical muscle tissue that contracts in multiple directions, mimicking the intricate patterns found in nature. This development opens up possibilities for bio-bots with improved range of motion, as these robots could squirm and wiggle through tight spaces where traditional machines cannot.
For years, researchers have been studying muscles as potential actuators for biohybrid robots, using soft, artificially grown muscle fibers. However, progress has been limited, as artificial muscle could only pull in one direction.
Now, MIT engineers have managed to create an artificial muscle tissue that twitches and flexes in coordinated directions. To demonstrate this, they built an artificial structure that generates force both concentrically and radially, much like the human iris dilates and constricts the pupil.
The researchers used a new "stamping" approach to achieve this. They 3D-printed a miniature, handheld stamp, patterned with microscopic grooves, each as small as a single cell. This stamp was then pressed into a soft hydrogel and seeded with real muscle cells. As the cells grew, they followed the grooves within the hydrogel, forming fibers that contracted in multiple directions when stimulated.
"By using the iris design, we have created the first skeletal muscle-powered robot able to generate force in more than one direction," says Ritu Raman, the Eugene Bell Career Development Professor of Tissue Engineering at MIT.
The stamp can be printed using tabletop 3D printers with different patterns of microscopic grooves. It can potentially be used to grow a variety of complex muscle patterns, similar to their natural counterparts.
Raman's lab at MIT aims to engineer biological materials that replicate the sensing, activity, and responsiveness of real tissues in the body. In addition to developing muscle tissue that can restore function to people with neuromuscular injuries, they are focusing on artificial muscles for use in soft robotics, such as muscle-powered swimmers with fish-like flexibility.
In the past, Raman's team has experimented with "hydrogel mats" that encourage muscle cells to grow and fuse into fibers without peeling away. They have also discovered ways to genetically engineer these cells to twitch in response to pulses of light and direct them to grow in long, parallel lines, similar to natural muscles.
However, designing artificial muscle that moves in multiple, predictable directions has been challenging. Natural muscle tissues do not just point in one direction, as the circular musculature in our iris and trachea, and even muscle fibers within our arms and legs do not point straight but at an angle. The team's stamping approach could help overcome this challenge by allowing for the growth of muscle fibers with multiple orientations.
Raman's team published their open-access results in the journal Biomaterials Science. The research was supported by the U.S. Office of Naval Research, the U.S. Army Research Office, the U.S. National Science Foundation, and the U.S. National Institutes of Health.
By using soft biological robots powered by advanced muscle tissue, it may be possible to develop more energy-efficient, biodegradable, and sustainable underwater robots in the future.
- This breakthrough in artificial muscle tissue could revolutionize the field of medicine, potentially improving the range of motion for bio-bots.
- The novel "stamping" approach developed at MIT could lead to the growth of a variety of complex muscle patterns, similar to their natural counterparts.
- The researchers' aim is to engineer biological materials that mimic the sensing, activity, and responsiveness of real tissues in the body.
- The team's focus extends beyond restoring function to people with neuromuscular injuries, as they also explore the use of artificial muscles in soft robotics.
- The team's research, published in the journal Biomaterials Science, received support from the U.S. Office of Naval Research, the U.S. Army Research Office, the U.S. National Science Foundation, and the U.S. National Institutes of Health.
- By using soft, advanced muscle tissue in underwater robots, there is potential to create more energy-efficient, biodegradable, and sustainable solutions in the future.
- The development of multi-directional artificial muscle tissue could solve the challenge of designing robots that accurately mimic the intricate patterns found in natural muscle tissues.
