New Direction (Air Chambers)

After Paul mentioned that he liked how the sponge was “squishy” and the concept was a lot less “skeletal” than previous cuddlebots with spinal-like movements, I decided to pursue this direction. It was through some research this week that I decided to pursue the idea of soft-bodied robots. In particular the concept of pneumatics, where one pushes air into silicone based bodies to cause a wide range of movements. In pursuit of this, I find an instructable to start on:

http://www.instructables.com/id/Air-Powered-Soft-Robotic-Gripper/

I will continue to work on this idea for the next few weeks to see if this is a viable idea for movement.

Following the previous week’s thoughts, for this prototype I tried to incorporate some type of resistance in between each of the vertebrae. For my initial pass I tried a combination of springs and various foams.

However, based on the results the wires were getting “stuck” and the shape was not returning back to it’s stationary position. In consultation with Paul, we decided to move forward with the foam material, but to drill channels into them for the wires to go through. The results are indicated below.

Summary

The foam material seems to work perfectly, I also like that the channels hide the wires. A servo base will need to be constructed for the bottom “vertebrae”, but this will be attempted farther along when more med-high fidelity prototypes are called for. Since this prototype still doesn’t afford the freedom of movement of “twisting” the spine, this movement will be my next big pursuit along with the idea of spinal fins that move independent of each other. This will be further explored next week.

First step that I took was to create a mood board of spinal images/designs that inspired me:

I then drew out some sketches of what some spinal movements could look like, focusing on prototype A to follow through on today:

I then quickly created a low-fi prototype of what this could look like in a physical form using tape, plastic sheeting, and some joint connectors made via mecho parts:

I used some string running through each part to guide the horizontal rotation around the joints (using a single fastener at only the top of the prototype).

SUMMARY:

In order to get the type of fine-tuned motion this prototype needs to be adapted so that EACH “vertebrae” is capable of moving independent of the other. This could be accomplished by having a thread fixture at each of the vertebrae instead of only having one fixture at the top and then looping said thread through all of the lower vertebrae. Also there needs to be some mechanism that restores the original spacing between each of the vertebrae. I believe this can be accomplished via springs and/or sponges.