Design and static testing of a compact distributed-compliance gripper based on flexure motion

A Reconfigurable Compliant Four-Bar Mechanism With Multiple Operation Modes

“…15c. Thus, the reconfigurable compliant gripper at hand unveils an ability to grasp a plethora of shapes unlike other compliant grippers in literature that exhibit only one of these modes of grasping [14,19]. Potential applications include micromanipulation and grasping lightweight and vulnerable materials like glass, resins, porous composites, etc.…”

“…Though there are abundant reconfigurable rigid-body mechanisms in the literature, the study of reconfigurable compliant mechanisms is limited. Hao studied the mobility and structure reconfiguration of compliant mechanisms [14] while Hao and Li introduced a position-spacebased structure reconfiguration (PSR) approach to the reconfiguration of compliant mechanisms and to minimize parasitic motions [15,16]. In this paper, one of the simplest yet ubiquitous parallel mechanisms, a planar equilateral four-bar linkage is considered at a constraint singularity configuration to synthesize a reconfigurable compliant four-bar mechanism.…”

Feasibility Study of a Gripper with Thermally Controlled Stiffness of Compliant Jaws

“…The symbol y s is the relative motion between the actuation displacement and the jaw's actual displacement, which is equal to the deformation displacement of the object; The symbol f y is the reaction force from the object when gripping occurs, which is equal to the gripping force. d is equal to 12/(T/L) 2 . p in is the initial internal axial force applied on each beam, which should be much larger than −10 in order to avoid first-order buckling, and will be induced by the thermal control in this paper.…”

“…The compliant gripper is a symmetrical design, where two jaws have rectilinear rigid-body motion towards the opposite direction to grip the object. Each half of this gripper is composed of two major compliant mechanisms: one is the parallel mechanism (actuation is imposed upon it) for guiding the jaw, so that the two jaws can only have parallel motions without producing slipping force on the object [2]; The other part is the jaw mechanism itself, which uses the symmetrical compound parallelogram mechanism [8] to change gripping stiffness. To control the stiffness, a simple heating coil is wrapped around the compliant beams of the jaw mechanism to dissipate heat for the beams.…”

“…Creating a gripper mechanism that applies exactly the right amount of force to grip such an object without breaking it can be done in several ways: one active approach is to use force sensing technology to accurately control actuation displacement [1,2], and another method is to use preloading displacement to generate a constant force from the jaw mechanism over a relatively large displacement range to accommodate the actuation inaccuracy [3]. The goal of this paper is to design and build a compact handheld compliant gripper that is simple enough to use and is capable of varying gripping force of the same actuation displacement (i.e., varying gripping stiffness) for grasping different objects.…”