Variable Stiffness Robotic Gripper Based on Layer Jamming

Introducing cutting-edge soft robotic grippers featuring variable stiffness through positive pressure layer jamming, revolutionizing object manipulation in diverse applications.

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The Need

Automation using robotics has taken many forms including, but not limited to, automotive manufacturing, transportation of good in shipping warehouses, and the delicate handling of wafers in semiconductor plants. In many of these applications grippers and end-of-arm-tools (EOAT’s) are incorporated to allow robotic arms to complete specific tasks. Largely due to these considerations, Mckinsey & Company recently reported that grippers and EOAT’s will grow from a $2.4 billion USD market in 2017 at a rate of 13-14% per annum to become a $5.1 billion USD market in 2023. Traditional rigid-body robotic grippers, however, consist of inflexible arms actuated by a large, unrestrained force. In this regard, damage to the product as well as danger to operators pose potential unwanted risks. Moreover, the rigid body nature of these grippers makes them less capable to handle items of unusual shapes, thereby limiting their applications. To address these concerns, some researchers have begun to develop soft robotic grippers which utilize a compliant structure and an actuating mechanism. Although much better suited for handling delicate and irregular objects, these soft grippers suffer from a limited loading capacity. In addition, many of these robotic grippers utilize complex designs and require expensive materials, thus reducing their feasibility as suitable alternatives. There is, therefore, a need for an easily implemented robotic gripper with tunable stiffness control for interacting with a wide variety of object geometries and materials.

The Technology

To address this need, researchers at The Ohio State University have developed a soft robotic gripper design that employs positive pressure layer jamming, a breakthrough technology enabling more efficient variable stiffness. The finger design comprises a flexible actuator, a flexible backbone, a rigid constraint frame, jamming layers, and a jamming bag. This innovative structure allows for precise control and adaptation to objects of varying shapes and sizes. Furthermore, the use of positive pressure instead of vacuum results in a much more reliable and efficient system.

Commercial Applications

  • Warehouse Automation: Efficiently handle and sort diverse packages with a single gripper.
  • Manufacturing: Enhance assembly line efficiency by manipulating objects of different weights and sizes.
  • Medical Robotics: Facilitate delicate procedures with the gripper's adaptable and gentle grasp.
  • Agricultural Robotics: Optimize harvesting processes by securely gripping fruits and vegetables.
  • Logistics and Material Handling: Streamline material transfer with the gripper's versatile capabilities.


  • Variable Stiffness: Achieve optimal gripping force, adapting to the specific requirements of different tasks.
  • Enhanced Payload Capacity: Overcome soft robot limitations, carrying heavier items without compromising safety.
  • Precision and Adaptability: Improve object manipulation in various industries with the gripper's versatile and controlled movements.
  • Cost-Efficiency: Reduce the need for multiple grippers by employing a single solution for diverse applications.
  • Advanced Manufacturing: Benefit from additive manufacturing, allowing for intricate designs and multi-material features.

Patent Protection

  • United States Patent Application No. 18/114,781 (Published)

  • PCT Patent Application No. PCT/US2023/063350 (Published)

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