Tactile sensors and methods
Various tactile sensors and associated methods are enabled. For instance, a sensing apparatus comprises a photosensitive sensor. A compound-eye structure is on the photosensitive sensor and an elastomer layer is on the compound-eye structure. A reflective layer is on the elastomer layer, opposite the compound-eye structure and a light source emits light between the reflective layer and the compound-eye structure.
1. A sensing apparatus, comprising:
a photosensitive sensor;
a compound-eye structure on the photosensitive sensor comprising an array of pinhole-based structures etched into a layer comprising the compound-eye structure;
an elastomer layer on the compound-eye structure;
a reflective layer on the elastomer layer, opposite the compound-eye structure; and
a light source that emits light between the reflective layer and the compound-eye structure.
2. The sensing apparatus of claim 1 , wherein the light source comprises a light emitting diode or an optical fiber.
3. The sensing apparatus of claim 1 , wherein the light source comprises a group of lights adjacently received at a side of each pinhole of the array of pinhole-based structures.
4. The sensing apparatus of claim 1 , further comprising markers received on a surface of the elastomer layer, opposite the compound-eye structure.
5. The sensing apparatus of claim 4 , wherein deformation of the sensing apparatus causes a marker of the markers to change position relative to the photosensitive sensor, and wherein the photosensitive sensor detects the change of position of the marker.
6. The sensing apparatus of claim 4 , wherein deformation of the sensing apparatus causes a marker of the markers to change position relative to the photosensitive sensor, wherein the photosensitive sensor detects the change of position of the marker, and wherein the change of position is used to determine a force distribution of an externally applied pressure that caused the deformation.
7. The sensing apparatus of claim 6 , wherein the force distribution of the externally applied pressure is determined based on at least one of a Young's modulus of the elastomer layer or based on a calibration of previously aggregated deformation images corresponding to different applied forces.
8. The sensing apparatus of claim 1 , further comprising a transparent rigid layer between the elastomer layer and compound-eye structure.
9. The sensing apparatus of claim 1 , further comprising a transparent protective layer on the reflective layer, wherein the transparent protective layer is a first transparent protective layer, and
wherein the sensing apparatus further comprises a second transparent protective layer received on the reflective layer, opposite the first transparent protective layer.
10. The sensing apparatus of claim 1 , wherein a pinhole-based structure of the array of pinhole-based structures comprises:
a first hole etched into a first side of the layer comprising the array of pinhole-based structures, and
a second hole etched into a second side of the layer comprising the array of pinhole-based structures, opposite the first side.
11. A tactile sensing apparatus, comprising:
a complementary metal oxide semiconductor sensor;
a pinhole structure of a layer on the complementary metal oxide semiconductor sensor, wherein the pinhole structure is etched into the layer;
an elastomer layer on the pinhole structure;
a reflective layer on the elastomer layer, opposite the pinhole structure; and
a light source on a surface of the elastomer layer.
12. The tactile sensing apparatus of claim 11 , further comprising a pinhole structure array, wherein the pinhole structure array comprises the pinhole structure.
13. The tactile sensing apparatus of claim 12 , wherein each pinhole structure of the pinhole structure array comprises a supporting square hole of a group of supporting square holes etched into the layer.
14. The tactile sensing apparatus of claim 13 , further comprising walls between each supporting square hole of the group of supporting square holes, wherein each wall of the walls prevents light entering a first supporting square hole of the group of supporting square holes from entering a second supporting square hole of the group of supporting square holes.
15. The tactile sensing apparatus of claim 11 , wherein motion of markers received on the elastomer layer are recorded by the complementary metal oxide semiconductor sensor and the motion is processed for use in a determination of deformation and force mapping.
16. The tactile sensing apparatus of claim 15 , wherein the complementary metal oxide semiconductor sensor is a first complementary metal oxide semiconductor sensor and the motion is cross-referenced with information received from a second complementary metal oxide semiconductor sensor to determine deformation and a slip ratio distribution of a surface to which the first complementary metal oxide semiconductor sensor and the second complementary metal oxide semiconductor sensor are attached.
17. A method for making a tactile sensor, comprising:
disposing a material layer on a photosensitive sensor;
etching a pinhole structure into the material layer;
disposing an elastomer layer on the pinhole structure, wherein the elastomer layer comprises markers on a surface of the elastomer layer;
disposing a reflective layer on the elastomer layer, opposite the pinhole structure; and
disposing a light source between the reflective layer and the pinhole structure.
18. The method of claim 17 , wherein the pinhole structure comprises a light passage.
19. The method of claim 17 , wherein the markers contrast with the reflective layer, and wherein the markers are distributed according to a pattern.
20. The method of claim 17 , wherein the pinhole structure comprises a circular hole etched into a first side of a material and a square hole etched into a second side, opposite the first side, of the material.