Electro-active polymers as robot leg actuators

spider project1



We found that electroactive polymers very interesting and promising technology. Most known family of electroactive polymers is of ones that can bend, shrink or stretch if you pass small electrical current through them. Obvious use is in an field of robotics as replacement for muscles. 

Here are some videos of existing laboratory models:

Actuating family of electroactive polymers if just one family of this materials. There are also materials that can change other characteristic when exposed to electrical current like viscosity (become sticky) and this is other thing  we want to use for this project.

What we want is to build something small but attractive based on electroactive polymers so we could later take more serious role in filed of modern robotics. So our choice is tiny robot spider because its easy to build in every aspect. 

Spider will have six legs and one utility arm. Each leg has 3 axis joint and 3 electroactive fibers that can shrink and relax to produce actuation in right direction. So each leg will be controlled by 9 electroactive fibers. Fiber will be packed around metal bone like we have in our own arms - bones and muscles around them. 

At end of each leg  there will be piece of electroactive gel that can change viscosity. This will enable it to climb the walls like real spider.

Utility arm will have needles that spider itself can plug into electric jack to recharge battery. This way spider could  stay on mission for long time because he could sneak to some electric jack to recharge himself. 

Spider will be capable of connecting to internet using 3G/4G or WIFI and will be able to transmit live audio/video form front and rear IC cam. Spider will be controlled by human via internet, but will be equipped with some autonomous moment algorithms for certain complicated moment operation, like stabbing utility arm needles into electrical jack , 180 degree turn, side walk...      


What can we expect form this project?

 - Spider can be mass produced. It can be offered to military, police, private eyes ... At the end it can be just cool toy. We expect one spider model cloud cost 2500-3500$ when mass produced. So we can expect we can profit for selling spider model .

- Having operating spider model will help us go further with other more complicated things. It will give us valuable technical data we would use to later more complicated products. Like in producing human, dog, cat ... artificial prosthetic replacement.

- Final goal is development of human sized droid equipped with artificial intelligence.


What can technically most difficult parts of development?

Crafting spider skeleton and bounding electroactive polymer fiber muscles to ti is certainly not easy task, but it is not most difficult.

One difficult task is choosing the right polymer compound. Some electroactive polymers react fast, some slow, some require more energy some less to operate. So we need to find right balance. Spider needs to move decently fast and to consume energy as low as possible because it depends on battery.     

Spider body carries  tiny computer powered by arm9 CPU and based on linux operating system. That tiny computer will execute all tasks needed for spider body to operate and move. 

Most difficult part is building software to control moments of spider. It has to synchronize and coordinate voltage on artificial muscles fibers so spider could move and stand steadily. Also it has to be adaptive because force put to actuation of each fiber will be almost always variable and will depend on terrain spider moves on at moment. This is also most valuable thing that will emerge form this project for later use. When we have right adaptive algorithm for controlling 63 fiber artificial muscles in spider, we will be able to adopt it to control something more complex that has ten time more fiber muscles in it.    


So from reading this text you can see honestly one goal is giving something new to the world that can help human kind,  it can become standard and of course other it can make profit. Maybe not much form spider project itself but certainly form moment coordination software we will develop form this.