The concept of artificial muscles is intriguing. Whether the purpose of lab-sourced musculature is greater strength or enhanced mobility for humans or robots, the idea is easy to grasp and the prospects are inspiring. We’ve written about researchers at the University of Illinois Department of Mechanical Science and Engineering working on rubber-reinforced carbon fiber muscles that can lift up to 12,600 times their weight. A team from the Wyss Institute at Harvard University and MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) created soft robotic artificial muscles able to move as much as 1,000 times their weight.

Scientists at Linköping University developed artificial muscles powered by glucose and oxygen, the same materials that power biological muscles. In a study published in Advanced Materials, the Swedish engineers explained that they used bio electrodes to convert chemical energy into electrical energy by integrating the electrodes into an electroactive polymer: polypyrrole. The artificial muscle has three layers: two layers of the polypyrrole with a thin membrane layer between them. When researchers apply a positive charge to one side of the structure, it expels ions and shrinks. As the other side gains ions from a negative charge, it in turn expands. The artificial muscle bends as the volume of the opposite layers change, just as animal muscles contract and relax.

The next steps at Linköping include further testing to control the muscle’s movement and working with other enzymes to help actuate the movement and to make it reversable. The work is still in very early stages, but the team already envisions a potential application using autonomous microrobots to monitor environmental conditions in lakes. It’s a leap from what would essentially be a sensor that didn’t require batteries to implanting muscle tissue in humans, but the potential is enormous.