Adaptive Self‐Sealing Suction‐Based Soft Robotic Gripper

Abstract

While suction cups prevail as common gripping tools for a wide range of real-world parts and surfaces, they often fail to seal the contact interface when engaging with irregular shapes and textured surfaces. In this work, the authors propose a suction-based soft robotic gripper where suction is created inside a self-sealing, highly conformable and thin flat elastic membrane contacting a given part surface. Such soft gripper can self-adapt the size of its effective suction area with respect to the applied load. The elastomeric membrane covering edge of the soft gripper can develop an air-tight self-sealing with parts even smaller than the gripper diameter. Such gripper shows 4 times higher adhesion than the one without the membrane on various textured surfaces. The two major advantages, underactuated self-adaptability and enhanced suction performance, allow the membrane-based suction mechanism to grip various three-dimensional (3D) geometries and delicate parts, such as egg, lime, apple, and even hydrogels without noticeable damage, which can have not been gripped with the previous adhesive microstructures-based and active suction-based soft grippers. The structural and material simplicity of the proposed soft gripper design can have a broad use in diverse fields, such as digital manufacturing, robotic manipulation, transfer printing, and medical gripping.

3D‐Printed Pneumatically Controlled Soft Suction Cups for Gripping Fragile, Small, and Rough Objects

“…The film material and thickness were selected to be a balanced trade-off between the maximum pull-off force and conformation to rough surface, as reported in our previous study. [29] The material of the gripper body was also stiffer than the one in our previous study. Unlike in our previous study, where the extremely soft material stretched significantly during the retraction and made the accurate positioning of the objects challenging, in this study the stiffer material reduces the stretching, and also prevents the gripper body to collapse on the soft film immediately after the withdrawal has been started.…”

“…In conclusion, we fabricated and characterized a 3D-printed soft suction cup gripper with a thin film underneath it. 3D-printing the gripper is faster and simpler than our previously [9,25,28,29] reported casting techniques: there are less fabrication steps, they take less time to complete, and they are more reproducible. This rapid prototyping also makes it easier to integrate our gripper into future applications in fully 3D-printed soft robotic systems including actuators and sensors.…”

“…In our previous works, [9,29] we proposed designs of soft cupshaped grippers with thin silicone elastomer films. The adhesion could be actively controlled by applying a negative pressure behind the film.…”

“…Two different films were demonstrated: a film with a gecko-inspired microfibrillar topography [9] and a flat nonstructured film. [29] The operation principle of the gecko-inspired gripper relied on adhesion control by equal load sharing, whereas in the flat film gripper, the film acts as a suction cup when a negative pressure is applied behind the film. This, combined with the adhesion of the object to the elastomeric film, creates the force necessary to pick an object.…”

Creating three-dimensional magnetic functional microdevices via molding-integrated direct laser writing

“…Each sample comprises of a 3 3 array of µM-bits. The measurements were conducted using a house-built setup 65 with a 25 mN load cell and a high-precision moving stage in the z -direction. The wafer was placed on the xy -stage directly underneath the load cell.…”