Does anyone know what happened to EAP's? It was such a new and promising material 3-5 years ago but all the gossip and news seems to have stopped?
Electroactive polymers? Very interesting things. Just discovered them, as a matter of fact.
I thought the technology would have matured well by now but it looks like its still stuck in the lab. If the technology was commercialized I could see a wide range of applications.
Its really a shame, It would be good if someone on here had some more information about what the current limitations/holdups are.
Its amazing to see people have still not heard about this amazing material even years after its development!
I saw a mention that Parker was coming out with an electrostrictive actuator. But the link from that was dead, not sure what that implies. Do a search for Dr. Adrian Koh, he has some interesting things to say about the potential of EA's. He also says he's developed a new dielectric elastomer that would allow a robot to lift 80 times its own weight. But I haven't seen any actual data, so you really have to guess what that means. He says the technology has the potential to develop actuators that would allow a robot to lift 500 times its own weight.
The biggest problem EA's face is their high operating voltage, a secondary problem is that they only convert a fraction of the energy used to charge them to mechanical energy. You can extract the energy from them to relax the actuator, but that demands a regenerative power supply, which complicates their use.
Acrylic dielectric EA's seemed to have a great potential, but the material used for most of these, 3M VHB 4910, has a very non-linear elastic behavior, which causes what has been termed snap-through instability. Dr. Koh also has a very good paper out there on analyzing elastomers for their suitability for use in EA's, definitely worth a read.
I experimented with EA's a little 14 years ago, I've tried to follow the field since then. I think the field is much better for experimenters now, in the availability of elastomers, elastic conductive materials, and high voltage transistors. I'd be fooling around with them now if I wasn't working on another project.
Fantastic reply Pharseid. I had a feeling that the high voltage requirements would be a huge issue (At least for my application) but I was not aware of the huge conversion inefficiencies. I really hope some progress is made in the next few years. I will be sure to look up Dr Adrian Koh and see what he has to say!
On the positive side, EA's can generate 20 times the actuation pressure of natural muscle and are capable of far greater contractions. So it may be worth dealing with their annoying problems for some applications. If you want some hands-on experience with these devices, a good starting point would probably be here: Dielectric Elastomer Actuators | Soft Robotics Toolkit