Facebook Technologies, LLC

Meta Platforms Technologies, LLC

Veryst Engineering LLC

Eric C Schmitt

Andrew John Ouderkirk

Katherine Marie Smyth

Nagi H Elabbasi

Kenneth Alexander Diest

Renate Eva Klementine Landig

Andrew Spann

Sheng Ye

Spencer Allan Wells

Tingling Rao

Bachir Ahmed Abeid

Sean S Teller

Jorgen S Bergstrom

Dennis Beynor

A drop tower apparatus and method of use is provided. The drop tower apparatus includes a base, a frame, a top member, rails, a sled, a triggering system, and a test fixture. The frame extends from the base. The top member is disposed on the frame opposite the base and has a winch. The rails extend from the base to the top member and are disposed within the frame. The sled is configured to slide vertically along the length of the rails and is releasably connected to the winch of the top member. The test fixture is configured to receive a sample for testing. The winch of the top member raises the sled to a desired height, the sled is released at the desired height and slides along the rails resulting in an impact on a sample placed in the test fixture.

System and method for high strain rate testing of material using gravity driven drop tower

An electroactive device may include (1) an electroactive polymer element having a first surface and a second surface opposite the first surface, the electroactive polymer element comprising a nanovoided polymer material, (2) a primary electrode abutting the first surface of the electroactive polymer element, and (3) a secondary electrode abutting the second surface of the electroactive polymer element. The electroactive polymer element may be deformable from an initial state to a deformed state by application of an electrostatic field produced by a potential difference between the primary electrode and the secondary electrode. Various other devices, systems, and methods are also disclosed.

Nanovoided electroactive polymer devices, systems, and methods

An actuator assembly includes a primary electrode, a secondary electrode overlapping at least a portion of the primary electrode, and an electroactive polymer layer disposed between the primary electrode and the secondary electrode, where the electroactive polymer layer includes a non-vertical (e.g., sloped) sidewall with respect to a major surface of at least one of the electrodes. The electroactive polymer layer may be characterized by a non-axisymmetric shape with respect to an axis that is oriented orthogonal to an electrode major surface.

Structured actuators: shaped electroactive polymers

An example device includes a nanovoided polymer element, a first electrode, and a second electrode. The nanovoided polymer element may be located at least in part between the first electrode and the second electrode. In some examples, the nanovoided polymer element may include anisotropic voids. In some examples, anisotropic voids may be elongated along one or more directions. In some examples, the anisotropic voids are configured so that a polymer wall thickness between neighboring voids is generally uniform. Example devices may include a spatially addressable electroactive device, such as an actuator or a sensor, and/or may include an optical element. A nanovoided polymer layer may include one or more polymer components, such as an electroactive polymer.

Nanovoided polymers having shaped voids

An example device includes a nanovoided polymer element, which may be located at least in part between the electrodes. In some examples, the nanovoided polymer element may include anisotropic voids, including a gas, and separated from each other by polymer walls. The device may be an electroactive device, such as an actuator having a response time for a transition between actuation states. The gas may have a characteristic diffusion time (e.g., to diffuse half the mean wall thickness through the polymer walls) that is less than the response time. The nanovoids may be sufficiently small (e.g., below 1 micron in diameter or an analogous dimension), and/or the polymer walls may be sufficiently thin, such that the gas interchange between gas in the voids and gas absorbed by the polymer walls may occur faster than the response time, and in some examples, effectively instantaneously.

Reduced hysteresis and reduced creep in nanovoided polymer devices

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Boston, MA, United States of America

Eric C Schmitt