Also, there are shape memory alloys and they are essentially a strand of synthetic muscle for a few dollars. You could concievable bundle them together to make a larger muscle, but you will probably have to do some active cooling if you want any sort of decent response curve and even then motors can be a lot faster.
What I think we could really do with is a linear actuator with a simple built in clutch that doesn't take power to hold a position.
You're absolutely correct re clutching actuators. There are a lot of robotics projects out there that combine small devices with limited mobility to create a larger (multicellular) robot with higher mobility. All of these projects stumble on that particular aspect: maintaining a lock without consuming power. M-Tran, Symbrion, Distributed Flight Array, ...
Also, there are shape memory alloys and they are essentially a strand of synthetic muscle for a few dollars. You could concievable bundle them together to make a larger muscle, but you will probably have to do some active cooling if you want any sort of decent response curve and even then motors can be a lot faster.
What I think we could really do with is a linear actuator with a simple built in clutch that doesn't take power to hold a position.