Worcester Polytechnic Institute

Cagdas D Onal

Weijia Tao

Marko B Popovic

Daniil Effraimidis

Brian Jennings

Gregory D McCarthy

Nicholas Corso

Onder Ondemir

William R Michalson

Alexander Caracappa

Fuchen Chen

Peerapat Luxsuwong

Tri Khuu

Saraj Pirasmepulkul

Ming Luo

Selim Ozel

Actuators and methods of use are provided. An actuator may include an inner member made from an elastic material and defining a compartment for receiving an actuating fluid, the inner member being moveable in a longitudinal direction from a relaxed state to an expanded state by introducing an actuating fluid into the inner member; and an outer member made from an inelastic material and being disposed around the elastic inner member to control expansion of the elastic inner member in a radial direction, the outer member being moveable from a folded relaxed configuration to an unfolded extended configuration as the inner member moves from the relaxed state to the expanded state, wherein the movement of the actuator between the relaxed state and the expanded state causes a movement of a structure to which the actuator is attached.

Actuators and methods of use

A soft bodied robotic member has the appearance of a finger and has a deformable rubber elongated body surrounding an array of rigid ribs interconnected by a perpendicular constraint. The plates form a series of parallel protrusions extending from opposed sides of the body and have a serrated, sawtooth or wavelike appearance. A tether runs through each row of protrusions and draws the corresponding protrusions together in a compressive manner to bend or dispose the finger toward the compressed side. Gaps between the protrusion allow movement of the protrusion towards adjacent protrusions to dispose the body in an arcuate shape. The constraint is a planar sheet that bends with the arc along its width, but resists lateral twisting, thus limiting movement outside a plane defined by the arc and the tether. Multiple finger members may be placed in close geometric proximity for gripping a common object.

Robotic gripper member

A toroidal actuator is responsive to a teleoperator for providing haptic feedback responsive to a curvature or articulated movement applied to a gripped object. The toroidal actuator surrounds an operator member such as a finger, and is responsive to pneumatic pressure for increasing telepresence force defined by resistance encounter against a teleoperated robotic claw. As the teleoperated claw grips an object, increased pneumatic pressure in the toroidal actuator tends to elongate the toroidal shape in a linear manner and oppose a curvature force applied by an inserted operator finger. Resistive force is based on soft sensing of the gripped object, thus the toroidal actuator applies an increasing resistive force to curvature as the robotic claw closes around a gripped object by solenoid regulated air pressure. A typical assembly includes at least 3 toroidal actuators for two digits and a thumb of an operator.

Haptic glove as a wearable force feedback user interface

A robotic configuration employs a system of low-cost, relatively lightweight beams and linkages fabricated from a planer material from a series of cuts and folds. The beams are folded along crease lines to form a 3-dimensional structure from a 2-dimensional substrate such as a polyester or other semi-rigid sheet. Tabs and appendages, or keys, cut into the planar material engage slots or apertures cut into adjacent members to define linkages. The linkages include tabs that are insertable in a one-way manner, such that removal is prevented but articulate and rotational movement is permitted by the resilient and flexible nature of the planar sheet material. An arrangement of beams and linkages are cut and formed based on a pattern imposed on a single planar sheet. The beam and linkage arrangement defines a robotic configuration for transport and other actions from an actuation source such as a motor.

Fabrication of robotic mechanisms and systems from planar substrates

A robotic sensing and touch apparatus detects gradual deformations in a resilient surface, in contrast to conventional rigid member displacement. Hall effect sensors coupled to rare-earth magnets in a deformable base allow sensing of surface curvature and compression against grasped objects. The deformable base, such as a silicone mold or other resilient encapsulation, fixes a magnetic source and an opposed Hall effect sensor. Calibration of a received magnetic field is defined by a sensor element voltage in an 'at rest' (undeformed) state, and at successive degrees of deformation resulting from compression of the deformable base that draws the magnet in different orientations relative to the Hall effect sensor. An array of magnet and sensor element pairs allows relative sensing over an area for detecting curvature of a translated or articulated member, or engagement with a curved surface.

Soft-body deformation and force sensing

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Allston, MA, United States of America

Cagdas D Onal