Surface Geometry Manipulation of Magnetically Stimulated Elastomers

Students

Engineering and Applied Sciences

Faculty

Professor and Chair of Mechanical Engineering and Applied Mechanics

Project Summary

I worked on a material known as a magnetorheological elastomer (MRE). The material behaves interestingly when exposed to a magnetic field. I set out to find shapes that would change the surface geometry of the MRE when a magnet was put near it.

I designed disks with shapes on one side using computer aided design (CAD) software. The disks had to fit into petri dishes that the material would be sitting in. I used 3D printing to make the disks I designed. I tried several designs starting with simple shapes like sine waves and square pillars. The hope was that the material would conform to the shape of the disk, making the surface geometry of the MRE the same shape as the shapes on the disk. However when a magnet was put close to these samples, there was no change.

After I realized that that method would not work I developed a new method. Instead of trying to get the material to conform to the surface I would subtract the geometries out of the surface. I made more 3D printed molds however this time the molds were meant to displace the material, leaving holes of different shapes in the surface. This processes worked. I made samples upon samples of MRE to find just the right shape to make. Eventually I settled upon molds that had cylindrical pillars. This left cylindrical holes in the surface of the MRE that changed in size with a magnetic field.

Once I got MRE samples with holes that changed with magnetic field, I measured how much they changed with the magnet. I wanted see how the magnet strength effected the size of the holes. To do this I needed a device that would move a magnet closer to a sample at controlled intervals. No such device existed for my specific application, therefore I made one. The design process was tedious but worthwhile. Eventually I made the device and took the measurements I needed.

I learned a lot during my research experience. At the beginning I had try different shapes and methods of changing the material. Through this process of trial and error, I learned to let curiosity lead my research. I had to fail countless times before I got a sample that showed any promise. Once I allowed my curiosity to fuel my research I learned more about the material than I could have ever hoped for. In making the device to measure my samples I learned to solve my own problems. There were no existing devices to do the specific tack that I needed so I had to take the initiative to make one. This research experience as a whole was extremely rewarding and gave me skills to be a great engineer.