Modular Adhesives And Energy-Dissipating Materials

Tech ID: 10126 / UC Case 1999-103-0

Brief Description

A modular, energy-dissipating material that prevents failure of adhesives, fibers and composite and other structures.

Background

Natural materials are renowned for their strength and toughness. Spider dragline silk has a breakage energy per unit weight two orders of magnitude greater than high tensile steel, and is representative of many other strong natural fibers. The abalone shell, a composite of calcium carbonate plates sandwiched between organic material, is 3,000 times more fracture resistant than a single crystal of the pure mineral. The organic component, comprising just a few percent of the composite by weight, is thought to hold the key to nacre's (or mother-of-pearl's) fracture toughness.

Description

Scientists at the University of California have developed a modular, energy-dissipating material that prevents failure of adhesives, fibers and composite and other structures. The modules include folded subunits or domains that unfold in a stepped fashion at forces below that necessary to break the backbone of the material and, with adhesive material, below that necessary to break the bonds that fasten the material to surfaces being glued..

Advantages

This newly discovered mechanism enables the development of materials with unique characteristics, including:

Adhesives or fibers that are not subject to catastrophic failure (i.e. breaking the molecular backbone of the adhesive or its attachments to the surface being glued);

Adhesives or fibers that can "heal" or refold once the force is reduced;

Adhesives or fibers designed to suit a specific need. For instance, modules that unravel at different forces could be used to produce adhesives that yield easily at first and then become more and more rigid;

Adhesives used to pull surfaces together. Surfaces could be glued under conditions where the modules are unfolded and then the modules could be caused to enter the folded state;

Smoothed force-verse-extension curves achieved using modules that unfold in multiple steps.

Applications

This modular elongation mechanism may prove to be quite general for conveying toughness to natural fibers and adhesives, including dragline silk. Although this behavior was discovered in a protein, it can be extended to human-made fibers and adhesives, such as those composed of block copolymers. It has applications ranging from armor to artificial tendons.

Patent Status

Country	Type	Number	Dated	Case
United States Of America	Issued Patent	6,376,636	04/23/2002	1999-103

Inventors

Deming, Timothy J.
Hansma, Paul K.
Kindt, Johannes H.
Morse, Daniel E.
Stucky, Galen D.

Other Information

Categorized As

Materials & Chemicals
- Other

Related cases

1999-103-0

Contact

Shaun R. Juncal / juncal@tia.ucsb.edu / tel: View Phone Number. Please reference Tech ID #10126.

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