A Stretchy, Self-Healing Artificial Muscle
spectrum.ieee.org
spectrum.ieee.org
That's not much expansion. Why such a weak electric field? If you crank up the electric field strength (1 watt/meter is easy to reach), does it expand more? Muscle polymers aren't new; much more powerful ones were developed almost two decades ago.[1]
This is one of those press-release derived articles. The actual press release [2] is more helpful. There's a video.[3] The high stretchyness is unusual, and the self-heading is useful, but the artificial muscle effect is weak. They're thinking of this more as a skin sensor than a muscle. That could be useful. Robot skin sensors have been built, but they're too fragile or too insensitive or too noise sensitive or need to be made in an IC fab and cost too much.
[1] http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=680638... [2] https://news.stanford.edu/2016/04/18/stanford-researchers-cr... [3] https://www.youtube.com/watch?v=nK0KsWHlW2U
It's interesting to compare it to natural self healing systems, which heal on a much higher scale (cellular).
The obvious difference is that artificial materials are molecularly homogeneous. But that homogenity precludes auto-determination of high level structure.
For example, my car paint may self heal, but it won't necessarily heal into a uniform coating because the individual units (in this case molecules) aren't guided to specific positions. In contrast, biological systems are much more robust because the placement of individual units (cells) is guided by a larger system.
That's why we still have a long way before our creations are truly 'self-healing'. Material science may ultimately not be part of the answer.