The major difference is that this air muscle will not use positive pressure to do the work it will use vacuum we will remove the air and in turn cause the device to retract.
This is a prototype and will be refined many many times. This device will be the main component in my next instructable The 3d printed robotic arm.
If I win the contest this will lead to a whole new type of printed robot. we will be able to print 80% of the mechanicals and reduce the assembly time of the arm. Thereby lowering costs and making the technology cheaper.
The outer shell will be covered with a silicone material that is airtight and will be secured to each of the end caps. also added will be a guide wire down the center of the muscle. this can be used as a feedback device to return information on muscle movement and distance. Again a major missing component to air muscles to date.