Rate responsive, stretchable devices further improvements

US9958023B2 · kind B2 · utility

Assignee

• The United States of America as represented by the Secretary of the Army · US

Inventors

• Eric D. Wetzel · Baltimore, US
• Paul T. Nenno · Murrysville, US

Key dates

• Filing date: Mar 1, 2016
• Grant date: May 1, 2018
• Expiry date: Mar 25, 2036

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16F13/10
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

Rate-dependent, elastically-deformable devices according to various embodiments can be stretched and recovered at low elongation rates. Yet they become stiff and resistive to stretching at high elongation rates. In one embodiment, a rate-dependent, elastically-deformable device includes an elastically-deformable confinement member; one or more filaments placed inside the elastically-deformable confinement member; and a fluid that substantially fills the remaining volume inside the elastically-deformable confinement member. The resistance force to extension of the device is designed to increase as the extension rate of the device increases. At low elongation rates the filaments can readily slide past each other. At high elongation rates, the fluid transforms to a less flowable material that greatly increases the force and energy required for elongation; or transforms to a non-flowable material that resists elongation. The devices thus can be stretched and recovered at low elongation rates, but become extremely stiff and resistive to stretching at high elongation rates.