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Remember the autofitting jacket from back to the future two? Answered

My friend and I are building a functional one for our senior engineering project. We've narrowed down the solutions to servos and cables or hydraulics. However, both of these are rather bulky. Any suggestions on what else we could do or more idealy how to shrink these systems? We we're thinking about using muscle fibers to contract a bladder instead of a pump for hydraulics, but that would be expensive and annoyingg to implement.


Muscle wire will not shrink all that much and generally relies on leverage to extend the movement - This isn't applicable to your project.

Inflating a balloon inside a braided mesh tube (as used to keep cables tidy) will provide quite a lot of movement and torque. This is used in shadow muscles actuators.

It should be possible to make and rig some small pneumatic actuators to pull wires in the seams.

As I understand it, they had several people in the movie who pulled on hidden cables that were inside the jacket to pull off this stunt.

Could you similarly rig a system of cables and pulleys that could achieve the same results? If the cables were placed inside a clear, flexible tubing, you could easily sew it into the jacket or use velcro to keep it in place and prevent the cables from getting hung up by the material. The cables themselves don't have to be very thick (just strong enough for the job) and therefor light enough to not create a lot of extra weight or bulk.

I hope this suggestion helps.

Is there a question in here??

"Any suggestions on what else we could do or more idealy how to shrink these systems?"