BACKGROUND

1. Field of Invention

The field of the currently claimed embodiments of this invention relates to self-folding structures, and more particularly to self-folding structures that are smaller than 1 cm in a folded configuration.

2. Discussion of Related Art

Over the last several years, self-folding methods for transforming lithographically patterned 2D templates into hollow microcontainers have been developed (B. Gimi, et al.,Biomed. Microdev.2005, 7, 341-345 (2005); T. G. Leong, et al.,Langmuir23:8747-8751 (2007)). These containers also feature precise patterning of pores in all three dimensions. Containers known in the art, however, have a primarily metallic composition to facilitate photolithographic patterning and wet etching. Although the metallic containers interact with electromagnetic fields to enable remote heating (H. Ye, et al.,Angew. Chem.46:4991-4994 (2007)) and imaging (B. Gimi, et al.,Cell Trans.16:403-408 (2007)), and containers coated with gold have been shown to be nontoxic to cells, such containers lack other important features, such as biodegradability and optical transparency. Polymers, however, remain the material of choice in constructing devices for cell encapsulation therapy, tissue engineering and drug delivery (S. Prakash, H. Soe-Lin,Trends Biomat. Artif. Organs,18:24-35 (2004)).

Therefore, there remains a need for improved self-folding structures and methods of producing the self-folding structures.

SUMMARY

A sub-centimeter structure according to an embodiment of the current invention includes a first structural component, a second structural component arranged proximate the first structural component, and a joint connecting the first and second structural components. The joint includes a material that has a first phase that is substantially rigid to hold the first and second structural components in a substantially rigid configuration while the material is in the first phase. The material of the joint has a second phase such that the joint is at least partially fluid to allow the first and second structural components to move relative to each other while the material is in the second phase. The joint interacts with the first and second structural components while the material is in the second phase to cause the first and second structural components to move relative to each other. And, the first and second structural components include a polymer.

An array according to an embodiment of the current invention includes a plurality of the above-noted sub-centimeter structures.

A composition according to an embodiment of the current invention includes a plurality of the above-noted sub-centimeter structures.

A method of producing a sub-centimeter structure according to an embodiment of the current invention includes providing a first structural component, providing a second structural component proximate the first structural component, providing a joint connecting the first and second structural components, and exposing the joint to heat such that the joint changes phase from a substantially solid material to an at least partially fluid material such that the joint interacts with the first and second structural components to cause the first and second structural components to move relative to each other in a substantially predetermined motion. The first and second structural components comprise a polymer.

