| |

Making Soft Robotics Stronger Improves VR Gloves, Opening New Applications

UPennRobotGloves400x275

November 30, 2022

Courtesy of Melissa Pappas, University of Pennsylvania

Soft robots, or those made with materials like rubber, gels and cloth, have advantages over their harder, heavier counterparts, especially when it comes to tasks that require direct human interaction. Robots that could safely and gently help people with limited mobility grocery shop, prepare meals, get dressed, or even walk would undoubtedly be life-changing. 

However, soft robots currently lack the strength needed to perform these sorts of tasks. Making soft robots stronger without compromising their ability to gently interact with their environment has limited the development of these devices. Penn Engineers at the University of Pennsylvania School of Engineering and Applied Science have devised a new electrostatically controlled clutch that enables a soft robotic hand to be able to hold four pounds, 40x more than the hand could otherwise lift. This required 125 volts, a third of the requirement for current clutches.

James Pikul, Assistant Professor in Mechanical Engineering, Kevin Turner, Professor and Chair of MEAM, and their Ph.D. students, David Levine, Gokulanand Iyer and Daelan Roosa, published a study in Science Robotics describing a new, fracture-mechanics-based model of electroadhesive clutches, a mechanical structure that can control the stiffness of soft robotic materials. Using this new model, the team was able to develop a clutch 63X stronger than current electroadhesive clutches. The model not only increased the force capacity of a clutch used in soft robots, it also decreased the voltage required, making soft robots both stronger and safer.

An electroadhesive clutch is a thin device that enhances the change of stiffness in the materials which allows the robot to perform this task. The clutch, similar to a clutch in a car, is the mechanical connection between moving objects in the system. In the case of electroadhesive clutches, two electrodes coated with a dielectric material become attracted to each other when voltage is applied. The attraction between the electrodes creates a friction force at the interface that keeps the two plates from slipping past each other. The electrodes are attached to the flexible material of the robotic hand. By turning the clutch on with an electrical voltage, the electrodes stick to each other, and the robotic hand holds more weight than it could previously. Turning the clutch off allows the plates to slide past each other and the hand to relax, so the object can be released.

Traditional models of clutches are based on a simple assumption of Coulombic friction between two parallel plates, where friction keeps the two plates of the clutch from sliding past each other. However, this model does not capture how mechanical stress is non-uniformly distributed in the system, and therefore, does not predict clutch force capacity well. It is also not robust enough to be used to develop stronger clutches without using high voltages, expensive materials, or intensive manufacturing processes. A robotic hand with a clutch created using the friction model may be able to pick up an entire bag of apples, but will require high voltages which make it unsafe for human interaction.

“Our approach tackles the force capacity of clutches at the model level,” says Pikul. “And our model, the fracture-mechanics-based model, is unique. Instead of creating parallel plate clutches, we based our design on lap joints and examined where fractures might occur in these joints. The friction model assumes that the stress on the system is uniform, which is not realistic. In reality, stress is concentrated at various points, and our model helps us understand where those points are. The resulting clutch is both stronger and safer as it requires only a third of the voltage compared to traditional clutches.”

“We haven’t seen many soft robots in our world yet, and that is, in part, due to their lack of strength, but now we have one solution to that challenge,” says Levine. “This new way to design clutches might lead to applications of soft robots that we cannot imagine right now. I want to create robots that help people, make people feel good, and enhance the human experience, and this work is getting us closer to that goal. I’m really excited to see where we go next.”

To learn more about, visit the Phys.Org Techxplore website here.

Photo Credit: University of Pennsylvania School of Engineering and Applied Science


Robotics World News

  • Seed Group and Ryberg Partner to Bring AI-Assisted Disinfection Technology to the Middle East

    Seed Group and Ryberg Partner to Bring AI-Assisted Disinfection Technology to the Middle East

    Netherlands-based Ryberg combines the latest in computer vision, robotics, and infection prevention-technologies to deliver intelligence and efficiency in disinfection. Ryberg has developed Disinfection Robots, which are self-driving disinfection machines. Ryberg’s patented Disinfection Engine makes intelligent disinfection decisions, allowing the robots to disinfect spaces for up to 6 hours—to bring a layer of defense in the… Read More…

  • Wind River and Airbus Collaborate on Certification of Automatic Air-to-Air Refueling (A3R)

    Wind River and Airbus Collaborate on Certification of Automatic Air-to-Air Refueling (A3R)

    Wind River, a global leader in delivering software for mission-critical intelligent systems, announced it has worked with Airbus to support the A330 Multi-Role Tanker Transport (MRTT) aircraft for automatic air-to-air refueling (A3R). The MRTT aircraft is the world’s first tanker to be certified for automatic air-to-air refueling boom operations in daylight. Airbus uses VxWorks 653 for the A330 MRTT… Read More…


Products for Robots & Cobots

  • Jabil, OSRAM, Artilux Develop Next-Generation 3D Camera Prototype

    Jabil, OSRAM, Artilux Develop Next-Generation 3D Camera Prototype

    Manufacturing solutions provider Jabil has announced that its optical design center in Jena, Germany, is currently demonstrating a prototype of a next-generation 3D camera with the ability to operate in both indoor and outdoor environments up to a range of 20 meters. The prototype was the result of a combination of proprietary technologies from Jabil,… Read More…

  • Product Profile: IDS CMOS Sensor IMX273

    Product Profile: IDS CMOS Sensor IMX273

    What is it? IDS cameras can be found in automotive, packaging, printing, and robotics industries, as well as in medical technology, traffic monitoring, security, kiosk systems, and logistics contexts.  The global shutter CMOS sensor IMX273 in the Sony Pregius series offers high image quality, high sensitivity and wide dynamic range. With a resolution of 1.58… Read More…