Magnetostrictive film actuators using selective orientation
View Patent ↗A method of making beams, clamps and other structures by curing a polymer containing a magnetostrictive material. A magnetostrictive material like TERFENOL-D™ is placed in a polymer. This mixture is put onto a slide in a film. The mixture is cured by UV light (or other means) so that it cross-links. A second layer of polymer with no magnetostrictive material can be cured on top of the first layer. This leads to a beam structure which exhibits a bending moment in an applied magnetic field. By aligning the magnetostrictive particles before curing with a magnetic field, a beam or other structure can be produced with aligned particles. A mask can be used to selectively cure regions where the magnetostrictive particles have different alignments on the same layer. It is possible to build up multiple layer structures with layers of magnetostrictive particles aligned in different directions.
1. A process for making a magnetostrictive actuator comprising the steps of:
mixing a magnetostrictive material with a UV curable polymer to form a material mixture;
placing a first film of said material mixture on a bottom slide;
partially curing said polymer with UV light in an oxygen free environment forming a partially cured layer;
placing a second film of said UV curable polymer on said partially cured layer and curing said second film, whereby said first and second films form a composite beam.
2. The process of claim 1 wherein said first and second films are further cured by heat.
3. The process of claim 1 further comprising aligning a portion of said first layer with a magnetic field prior to curing.
4. The process of claim 1 wherein said UV light is around 364 nm wavelength.
5. The process of claim 1 further comprising using a plurality of said beams made by said process arranged in a predetermined pattern to make a clamp actuator.
6. A method of forming a magnetostrictive actuator comprising the steps of placing a magnetostrictive material and a cross-linking polymer on a base, aligning said magnetostrictive material in a first direction with a magnetic field, curing at least one region of said polymer, aligning magnetostrictive material in uncured regions of said polymer in a second direction with a magnetic field, curing at least one second region of said polymer, whereby at least two regions of cured polymer are created with magnetostrictive material aligned in at least two different directions.
7. The method of claim 6 further comprising curing a top layer of polymer on said previously cured polymer, where said previously cured layer of polymer contains magnetostrictive material and said top layer of polymer contains almost no magnetostrictive material.
8. The method of claim 6 wherein said curing is by UV light.
9. The method of claim 8 wherein said UV light has a wavelength of around 364 nm.
10. The method of claim 6 wherein said first region of polymer is selected with a mask.
11. A method of producing a magnetostrictive actuator comprising the steps of placing a first polymer layer on a glass slide, said first polymer layer containing a magnetostrictive material, curing at least a portion of said polymer on said slide, placing a second polymer layer on said first polymer layer, curing said second polymer layer.
12. The method of claim 11 wherein said curing is with a UV light source.
13. The method of claim 12 wherein said UV light source has a wavelength of around 364 nm.
14. The method of claim 11 further comprising placing a sheet magnet under said glass slide before said curing.
15. The method of claim 11 further comprising placing a second glass slide over said polymer layers during curing.
16. The method of claim 11 further comprising making multiple layers of polymer with magnetostrictive material and polymer without magnetostrictive material.
17. The method of claim 16 wherein at least two of said layers with magnetostrictive material are aligned in different directions.