Hearing-aid transducer having an engineered surface
View Patent ↗A hearing aid transducer adapts itself to variations in the surface of a tympanic membrane and slides over the migrating membrane without lubrication. Microscopic setae create a conforming interface between the biocompatible material of the transducer and the living tissue of the tympanic membrane.
1. A hearing aid transducer comprising:
a biocompatible carrier having a surface shaped to fit a tympanic membrane or ear canal; and,
a driving element attached to the carrier;
wherein,
the surface supports a plurality of microscopic setae that are angled with respect to the surface in a pattern that corresponds to a migration pattern of the tympanic membrane.
2. The transducer of claim 1 wherein the density of setae is greater than 100 per square millimeter.
3. The transducer of claim 1 wherein the setae have a length between 10 and 200 microns.
4. The transducer of claim 1 wherein the setae have an aspect ratio greater than 10.
5. The transducer of claim 1 wherein the setae have a Young's modulus between about 0.01 GPa and 10 GPa.
6. The transducer of claim 1 wherein the biocompatible carrier is made of silicone, fluoro-silicone, rubber, or other flexible materials.
7. The transducer of claim 1 wherein the driving element receives electrical power from a photovoltaic cell.
8. The transducer of claim 1 wherein the driving element comprises a coil and a permanent magnet.
9. The transducer of claim 1 wherein the driving element comprises a piezoelectric bimorph.
10. The transducer of claim 1 wherein tips of the setae have a spherical shape.
11. The transducer of claim 1 wherein tips of the setae have a flat shape.
12. The transducer of claim 1 wherein tips of the setae have a cupped shape.
13. The transducer of claim 1 wherein tips of the setae have a foot shape.
14. The transducer of claim 1 wherein tips of the setae have a filament shape.
15. The transducer of claim 1 wherein the setae are equipped with a plurality of spatulas.
16. A method for forming an interface between a living tissue and a biocompatible surface comprising:
providing a biocompatible surface;
forming a plurality of setae on the surface;
orienting the setae according to a migration pattern of tissue upon which the biocompatible surface is to be placed.
17. The method of claim 16 wherein the surface is a surface of a hearing aid transducer and the tissue is the epithelium of a tympanic membrane.
18. The method of claim 16 wherein the forming is accomplished by making the surface and the setae from liquid elastomer using a mold.
19. The method of claim 16 wherein the setae are equipped with a plurality of spatulas.
20. The method of claim 19 wherein the spatula are fabricated using carbon nanotube fabrication technology.