Self-assembly is a promising technique to overcome fundamental limitations with integrating, packaging, and general handling of individual electronic-related components with characteristic lengths significantly smaller than 1 mm. Here we describe the use of magnetic and capillary forces to self-assemble 280 µm sized silicon building blocks into interconnected structures which approach a three-dimensional crystalline configuration. Integrated permanent magnet microstructures provided magnetic forces, while a low-melting-point solder alloy provided capillary forces. A finite element model of forces between the magnetic features demonstrated the utility of magnetic forces at this size scale. Despite a slight departure from designed dimensions in the actual fabricated parts, the combination of magnetic and capillary forces improved the assembly yield to 8%, over approximately 0.1% achieved previously with capillary forces alone.
Self-assembly is a promising technique to overcome fundamental limitations with integrating, packaging, and generally handling individual electronic-related components with characteristic lengths significantly smaller than 1 mm. Here we briefly summarize the use of capillary and magnetic forces to realize two example microscale systems. In the first example, we use capillary forces from a low melting point solder alloy to integrate 500 μm square, 100 μm thick silicon chips with thermally and chemically sensitive metal-polymer hinge actuators, for potential medical applications. The second example demonstrates a path towards self-assembling 3-D silicon circuits formed out of 280 μm sized building blocks, utilizing both capillary forces from a low melting point solder alloy and magnetic forces from integrated, permanent magnets. In the latter example, the utilization of magnetic forces combined with capillary forces improved the assembly yield to 7.8% over 0.1% achieved previously with capillary forces alone.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.