Adhesive gripper comprising a shape memory polymer for pick- and-place applications

{
  "publication_number": "US12365816B2",
  "country": "US",
  "kind": "B2",
  "title": "Adhesive gripper comprising a shape memory polymer for pick- and-place applications",
  "abstract": "An adhesive gripper for pick-and-place maneuvers comprises one or more legs, where each leg terminates in a foot rotatably connected to the respective leg. Each foot includes a SMP dry adhesive comprising a shape memory polymer, and a rigid backing layer attached to a back side of the SMP dry adhesive, such that a front side of the SMP dry adhesive is available for attachment and release of objects. The adhesive gripper further includes a handle portion connected to the one or more legs, a release mechanism comprising a release ring within the handle portion, and one or more releasing rods integrated with the one or more legs for release of an object onto a substrate.",
  "claims": [
    "1. A foot of an adhesive gripper for pick-and-place maneuvers, the foot comprising: a shape memory polymer (SMP) dry adhesive comprising a shape memory polymer and having a front side for the attachment and detachment of objects, the shape memory polymer having a first stiffness; a soft polymer layer on a back side of the SMP dry adhesive, the soft polymer layer having a second stiffness less than the first stiffness; and a rigid backing layer attached to the soft polymer layer.",
    "2. The foot of claim 1, wherein the front side of the SMP dry adhesive comprises a planar adhesion surface.",
    "3. The foot of claim 1, wherein the front side of the SMP dry adhesive comprises a nonplanar adhesion surface.",
    "4. The foot of claim 1, wherein the nonplanar adhesion surface comprises a release tip to facilitate release of objects.",
    "5. The foot of claim 1, further comprising a heating and/or cooling mechanism secured to the rigid backing layer.",
    "6. The foot of claim 1, wherein the soft polymer layer comprises an elastomer or a shape memory polymer.",
    "7. The foot of claim 1, wherein the SMP dry adhesive has a dual structure comprising the shape memory polymer having the first stiffness and further comprising a second shape memory polymer having a third stiffness, the first stiffness being higher than the third stiffness, wherein the shape memory polymer is disposed at a center of the SMP dry adhesive and the second shape memory polymer is disposed along a perimeter of the SMP dry adhesive.",
    "8. An adhesive gripper for pick-and-place maneuvers, the adhesive gripper comprising: one or more legs, each leg terminating in a foot rotatably connected to the respective leg, each foot comprising: a SMP dry adhesive comprising a shape memory polymer; and a rigid backing layer attached to a back side of the SMP dry adhesive, a front side of the SMP dry adhesive being available for attachment and release of objects, a handle portion connected to the one or more legs; a release mechanism comprising a release ring within the handle portion and one or more releasing rods integrated with the one or more legs for release of an object onto a substrate.",
    "9. The adhesive gripper of claim 8, wherein each foot is rotatably connected to the respective leg by a ball joint.",
    "10. The adhesive gripper of claim 8, wherein each of the one or more releasing rods is slidingly connected to the respective leg, and wherein a pulling force applied to the release ring is transferred to the one or more releasing rods as a force directed into the substrate, thereby facilitating release of the object.",
    "11. The adhesive gripper of claim 8, wherein the shape memory polymer is a first shape memory polymer, and wherein the SMP dry adhesive has a dual structure comprising the first shape memory polymer having a first stiffness and a second shape memory polymer having a second stiffness, the first stiffness being higher than the second stiffness.",
    "12. The adhesive gripper of claim 11, wherein the first shape memory polymer is disposed at a center of the SMP dry adhesive and the second shape memory polymer is disposed along a perimeter of the SMP dry adhesive.",
    "13. The adhesive gripper of claim 8, wherein the shape memory polymer has a first stiffness, and further comprising a soft polymer layer on the back side of the SMP dry adhesive between the SMP dry adhesive and the rigid backing layer, the soft polymer layer having a second stiffness less than the first stiffness, and the rigid backing layer being attached to the soft polymer layer.",
    "14. A method of using the adhesive gripper of claim 8 for a pick-and-place maneuver, the method comprising: engaging the handle portion to move the adhesive gripper to a pick-up position where at least one foot is in contact with an object; heating the SMP dry adhesive of the at least one foot above a glass transition temperature thereof, thereby transitioning the shape memory polymer to a rubbery state, and applying a pressing force to the handle portion, thereby compressing the SMP dry adhesive from an undeformed configuration to a deformed configuration while in contact with the object; cooling the SMP dry adhesive, thereby transitioning the shape memory polymer to a glassy state and binding the object to the SMP dry adhesive in the deformed configuration; engaging the handle portion to pick up and move the object bound to the SMP dry adhesive to a desired position for placement onto a substrate; and heating the SMP dry adhesive above the glass transition temperature to induce a return to the undeformed configuration while applying a pulling force to the release ring to press the one or more releasing rods into the substrate, thereby releasing the object bound to the SMP dry adhesive onto the substrate."
  ],
  "description_excerpt": "The present disclosure is related generally to shape memory polymer adhesives and more particularly to a gripper comprising a shape memory polymer.\n\nRobotic grippers have highly been explored for numerous applications in diverse fields. The aerospace industry may require gravity-independent or zero-gravity grippers to use in space. Electronics companies may employ pick-and-place robotic grippers to assemble devices using surface mounting technologies. The manufacturing or logistics industry also has a strong demand for grippers to lift heavy objects or to do repetitive manipulations that lessen the burden of human workers. Microassembly utilizing grippers may enable unique three-dimensional microelectromechanical systems (MEMS) that cannot be achieved using other conventional approaches.\n\nIn an effort to satisfy the aforementioned demands, various mechanisms for robotic grippers have been introduced. Finger grippers may be simple yet effective when optimized by choosing the number of fingers and the shape of their gripping motions with appropriate actuation methods, and soft grippers show favorable performance since they resemble real human fingers. However, both finger and soft grippers have a common drawback, in that the target objects they lift must have multiple surfaces with acceptable dimensions to be gripped. Using microspine grippers may be a great choice to interact with rough surfaces such as rocks, but they may not be capable of working with smooth surfaces. While electromagnetic grippers have a benefit of easy and fast lifting and releasing, they are limited to lifting objects made of ferrous materials.",
  "cpc": [
    "C09J 7/35",
    "B25J 15/008",
    "B32B 27/12",
    "C08G 2650/50",
    "C08G 59/226",
    "C08G 59/504",
    "C09J 163/00",
    "C09J 2463/00",
    "C09J 5/06"
  ],
  "ipc": [
    "C09J 7/35",
    "B32B 27/12",
    "C09J 5/06"
  ],
  "assignees": [
    "University of Illinois System"
  ],
  "inventors": [
    "Seok Kim",
    "ChangHee Son"
  ],
  "filing_date": "2021-05-14",
  "publication_date": "2025-07-22",
  "grant_date": "2025-07-22",
  "priority_date": "2020-05-19",
  "application_number": "US-202117320720-A",
  "family_id": "78607769",
  "cited_by_count": 1,
  "citations": [
    "US20120007375A1",
    "US9815261B2",
    "US20150352586A1",
    "US20150359043A1",
    "US20180100046A1",
    "US20180179421A1",
    "WO2018144618A1"
  ]
}