Soft, adaptive, self-cleaning electrostatic gecko-like adhesive and gripper

{
  "publication_number": "US11872691B2",
  "country": "US",
  "kind": "B2",
  "title": "Soft, adaptive, self-cleaning electrostatic gecko-like adhesive and gripper",
  "abstract": "An adhesive apparatus with an electrostatic adhesive including a microstructured adhesive disposed over an electrode and/or a piezoelectric element. The adhesive can be added to any robotic gripper, such as a gripper finger formed of a flexible material and including a grip surface. The electrode and/or a piezoelectric element can be used for applying an electrostatic field and/or ultrasonic vibration, configured for cleaning the microstructured adhesive, releasing the adhesive, and/or sensing a load on the adhesive apparatus.",
  "claims": [
    "1. An adhesive apparatus, comprising an electrostatic adhesive configured to attach to a contact surface and provide adhesion between the contact surface and an object, the electrostatic adhesive including a microstructured adhesive disposed and layered over an electrode and/or a piezoelectric element, wherein the electrode and/or the piezoelectric element is disposed between the microstructured adhesive and the contact surface.",
    "2. The apparatus of claim 1, further comprising: a gripper finger formed of a flexible material and including a grip surface; and an adhesive pad on the grip surface, the adhesive pad comprising the electrostatic adhesive.",
    "3. The apparatus of claim 1, wherein the microstructured adhesive comprises a plurality of triangular wedges.",
    "4. The apparatus of claim 1, further comprising a dielectric and/or an insulator disposed between the electrode and the microstructured adhesive.",
    "5. The apparatus of claim 1, further comprising a layer of electrodes arranged in a pattern and with signal connections configured to provide a plurality of different controllable electrostatic field configurations.",
    "6. The apparatus of claim 1, further comprising the piezoelectric element in combination with the microstructured adhesive.",
    "7. The apparatus of claim 6, wherein the piezoelectric element is adapted to electrostatically repel dust from the adhesive, release the adhesive, and/or act as a force/contact sensor for the gripper.",
    "8. A method of operating the electrostatic adhesive according to claim 1, comprising a step of applying to the adhesive an electrostatic field and/or ultrasonic vibration, configured for cleaning the adhesive, releasing the adhesive, and/or sensing a load on the adhesive.",
    "9. The method of claim 8, wherein electrostatic forces and/or ultrasonic vibrations repel dust particles adhered to the adhesive.",
    "10. The method of claim 8, further comprising cleaning the adhesive with ultrasonic vibration from a piezoelectric device.",
    "11. The method of claim 8, further comprising changing an electrostatic field configuration with and across a layer of electrodes arranged in a pattern.",
    "12. The method of claim 8, further comprising changing the electrostatic field between resonant modes to provide a displacement for cleaning.",
    "13. The method of claim 8, further comprising removing an electrostatic force from the adhesive to release the adhesive.",
    "14. The method of claim 8, further comprising determining a load of the adhesive from an output voltage of a piezoelectric device in combination with the adhesive.",
    "15. The apparatus of claim 2, further comprising a foam layer disposed between the adhesive pad and the grip surface.",
    "16. The apparatus of claim 2, further comprising: a hinged finger joint at a base end of the gripper finger; and a motor connected to the gripper finger and configured to move the gripper finger about the hinged finger joint, wherein the motor comprises a stepper shaft disposed between two or more gripper fingers.",
    "17. The apparatus of claim 2, further comprising: a finger holder including or connected to two hinged finger joints each connected to one of the gripper finger or a second gripper finger; and a motor connected to the finger holder and configured to simultaneously move the gripper finger and the second gripper finger, each about a corresponding one of the hinged finger joints.",
    "18. The apparatus of claim 3, wherein each of the plurality of triangular wedges comprises a smooth cap tip.",
    "19. The apparatus of claim 1, further comprising: an array of electrodes under the microstructured adhesive; and a piezoelectric element on an opposite side of the array of electrodes from the microstructured adhesive.",
    "20. The apparatus of claim 19, further comprising a dielectric layer between the array of electrodes and the piezoelectric element.",
    "21. The apparatus of claim 1, wherein the electrode and/or the piezoelectric element is adapted to electrostatically and/or ultrasonically clean the microstructured adhesive."
  ],
  "description_excerpt": "This invention relates generally to using electrostatic and/or ultrasonic techniques to clean dust and other contaminants, and more particularly to methods, device, and systems of using electrostatic or the combination of electrostatic and ultrasonic techniques to clean gecko-like, micro-structured adhesives.\n\nThere has been considerable demand for controllable (i.e., on/off) adhesives for robotic grippers, climbing robots, and perching drones that can operate on a wide variety of surface materials and roughness. Directional gecko-like adhesives (also known as dry, microstructured, bio-inspired, fibrillar, or insect-inspired adhesives, among others) are a type of controllable adhesive that has shown to work well on a variety of surfaces. However, most of these microstructured adhesives have, for the most part, been tested in laboratory environments, with carefully cleaned surfaces and adhesives; the research neglects to account for the effect of dust that accumulates on the pads and can significantly decrease the adhesion.\n\nCleaning of microstructured surfaces generally falls into two categories: minimizing dust adsorption through adhesive design and removing dust particles that adhere to the surface. Dust adsorption on a microstructured surface can be minimized through several methods, including making the microstructured features smaller than the size of the contaminants, increasing the roughness of the surface, and using stiff materials that have low surface energy. These methods decrease dust adsorption but unfortunately, also decrease adhesion to a substrate.",
  "cpc": [
    "B25J 15/008",
    "B06B 1/0662",
    "B25J 15/022",
    "B25J 15/086",
    "B25J 15/12",
    "B25J 19/0058",
    "C09J 2301/31",
    "C09J 7/00",
    "C09J 7/20",
    "G01N 27/60",
    "H10N 30/073",
    "H10N 30/1051",
    "H10N 30/302",
    "H10N 30/704",
    "H10N 30/87"
  ],
  "ipc": [
    "B06B 1/06",
    "B25J 15/00",
    "B25J 15/08",
    "C09J 7/20",
    "G01N 27/60",
    "H10N 30/00",
    "H10N 30/87"
  ],
  "assignees": [
    "Illinois Institute of Technology"
  ],
  "inventors": [
    "Vahid ALIZADEHYAZDI",
    "Matthew Spenko"
  ],
  "filing_date": "2020-04-23",
  "publication_date": "2024-01-16",
  "grant_date": "2024-01-16",
  "priority_date": "2019-04-24",
  "application_number": "US-202016856515-A",
  "family_id": "72921195",
  "cited_by_count": 1,
  "citations": [
    "JP2000100920A",
    "US20060220403A1",
    "US20130180448A1",
    "US20170162780A1"
  ]
}