Reduced hysteresis and reduced creep in nanovoided polymer devices

US11133455B2 · kind B2 · utility

Assignee

• Facebook Technologies, LLC · US

Inventors

• Andrew Spann · Needham, US
• Eric Schmitt · Needham, US
• Nagi Hosni Elabbasi · Framingham, US
• Kenneth Diest · Kirkland, US
• Katherine Marie Smyth · Seattle, US
• Renate Eva Klementine Landig · Seattle, US
• Andrew John Ouderkirk · Kirkland, US

Key dates

• Filing date: Dec 4, 2019
• Grant date: Sep 28, 2021
• Expiry date: Jan 10, 2040

Classification

• Technology area (CPC G): Physics
• CPC primary: G02F2202/022
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

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.