Muscles are present everywhere in the body and are needed for all movements, both voluntary and involuntary. Ultimately, muscles are under the control of the nervous system, that connects its neurons to all muscles in the body. By sending out neural signals, muscles can contract resulting in movement. There are various diseases that affect muscle function, and many of them are caused by a defect in the nervous system. To restore muscular signalling, scientists from Linköping University have developed a chip that allows for artificial muscle contraction, thereby restoring movement. And by doing that, they have created a whole new chip technology.
Muscle control by a chip was made possible by utilizing the same sort of molecules that neurons normally use for their communication with muscles. All voluntary muscle movements are made possible using acetylcholine, which is produced at the tips of the neural connections coming from the central nervous system. The chip developed by Linköping University basically functions in the same way, as it controls the delivery of this so-called neurotransmitter.
Normally, electronic devices function by movement of electrons, hence the name electronics. The muscle chip is rather different, however, as it uses ions in its circuits. Ions are electrically charged variants of atoms and molecules, and can either be positively or negatively charged. By using ions instead of electrons, the scientists have much more flexibility with circuit development. Because theirs is based on acetylcholine, release of this substance does not only function inside the circuit, but also controls muscle movement.
A chemical chip such as the one developed by Linköping University could be implanted in muscle that is no longer under the control of the nervous system. By controlling the release of acetylcholine, dysfunctional muscles could be put to work again. Additionally, this new type of chip brings on a whole new area of electronics working with ions instead of electrons. By making them more complex, they can be made more broadly applicable. Use of different ions could potentially make them useful for activating other processes in the body, as there are many different messenger molecules.