Decelerate Strap

What is the Core Technology?

The Decelerate Strap consists of Shear Thickening Fluid (STF) enclosed within an elastomeric tube, with two ribbons attached to opposite ends of the tube and immersed in the enclosed STF. They have the capability to react to different forces, at low forces the straps allow for easy and comfortable movement, but at high forces they are resistant to allow for improved control. The Decelerate Strap will be implemented into various head, neck and body restraints to reduce violent head, neck and brain motion during a sudden change in acceleration or dangerous impact.

Strap_details

What is Shear Thickening Fluid (STF)?

STF exhibits fluid-like properties at low deformation rates, but solid-like properties at high deformation rates. Unlike Newtonian fluids, in which viscosity is independent of shear rate, STFs exhibit a viscosity that increases with increasing shear rate or stress. Dilatant’s Shear Thickening Fluid is a proprietary recipe that has been formulated by a team of PhD scientists to provide precise force control and long-term stability.

STF_Shear_Charts

What is the bottom line difference?

At slow deformations, the shear rates created by the moving elastomeric tube and the ribbons sliding past each other are below the STF’s critical shear rate, so the device extensional resistance is relatively low. During fast deformations, the shear rates created by the moving ribbons and tubes exceed the critical shear rate of the enclosed STF, creating high shear stresses that drastically increase the extensional resistance of the device. A key feature of the device is that the STF is enclosed within an elastomeric tube, which allows the device to be completely sealed and self contained unlike dashpot or piston devices, which rely on wiping seals that are unlikely to be robust or compact. Furthermore, the elastomeric tubing provides elastic recovery force, so that when force is removed from an extended device, it returns to its initial un-extended state.

…stretches easily at low speeds…

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…but resists stretching at high speeds…

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