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PhD Thesis Defense: Andrew A. Stanley: Haptic Jamming: Controllable Mechnical Properties in a Shape-Changing User Interface

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March 18, 2016 - 2:00pm
Peterson Building, Room 200 (550-200)

Free

Light refreshments preceed the talk at 1:45

Abstract

Haptic interfaces increase the richness and quality of user interaction with a virtual or remote environment by conveying physical information through the sense of touch. Beyond vibration of a mobile device or force feedback through the end effector of a robot, shape-changing interfaces provide more complete haptic feedback by allowing the user to explore the interface directly with his or her hands. This thesis presents the design, modeling, and control of a novel form of haptic interface inspired by advances in soft robotics and tangible interaction.

Haptic Jamming is a technique that combines particle jamming and pneumatic actuation of a surface to achieve simultaneous control of its shape and mechanical properties. A hollow silicone membrane is molded into an array of thin cells, each filled with coffee grounds such that adjusting the vacuum level in any individual cell rapidly switches it between flexible and rigid states. The array clamps over a pressure-regulated air chamber with internal mechanisms designed to pin the nodes between cells at any given height, which provide an extra degree of control over the output shape. Various sequences of cell vacuuming, node pinning, and chamber pressurization allow the surface to balloon into a variety of shapes.

Experiments were performed to define the rheological characteristics of jammed systems from a macroscopic perspective that is relevant to force-displacement interactions that would be experienced by human users, expanding upon existing physical models of jamming at the inter-particle level. This provides the framework to tune and control the mechanical properties of a jamming interface. A custom spring-mass deformable body simulation was built combining models of the three actuation inputs of a Haptic Jamming surface: node pinning, chamber pressurization, and cell jamming. The simulation guided the development of an algorithm to generate a sequence of actuation inputs for the surface in order to match desired output shapes ranging from topographical maps to three-dimensional solid object models.

The construction of multi-cell arrays integrated with the depth map from an RGB-D sensor provides the capability to close the feedback loop on surface shape, resulting in a more compelling display of complex shapes. Future research shows promise to develop Haptic Jamming into a fully three-dimensional device with embedded stretchable sensors, permitting its use as both a computer input and output interface. This technology can enable dynamic tangible environments for applications ranging from medical simulation to product design.

PhD Advisor: Allison Okamura

Contact Email: 
aokamura@stanford.edu