Speed Bumps

Close up of speed bump test

Figure 1.  Speed Bumps Device showing several test sites.  This device was built by embossing a plastic sheet with a machined stainless master mold.

WLI Image of a 9.2 micron speed bumpFigure 2.  White Light Interferometry (WLI) cross sectional image of a speed bump, 9.2 microns high.

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This device uses a series of ridges, embossed on a polymer substrate, to stimulate the Pacinian mechanoreceptors in the digit when the subject rubs perpendicular to the ridge length.

The test plate includes a series of sites with ridges of different heights.  The ridge heights of the sites range from 0.5 microns to 35 microns.  The subject's threshold of detection is determined by the smallest height ridges that they are able to identify.  The device is useful for rapidly testing both the toes and fingers.

We are exploring various methods for manufacturing the Speed Bumps, including micromachining, photolithographic techniques (LIGA-like), electro-chemical machining, hot embossing and injection molding.

U.S. Patent No. 8,133,189 B2 (issued Mar. 13, 2012).