Babak Parviz of University of Washington, named by Technology Review as one of this year’s outstanding innovators under the age of 35, writes in the Sept/Oct issue (free reg req’d) about self-assembly:
In nature, components “self-assemble” to yield complex functional systems. Inspired in part by this observation, a number of research groups are working to enlist self-assembly as a method for producing functional products across size scales. The hope is to create a new paradigm in mass manufacturing in which self- assembly replaces assembly of parts one by one. We believe that, in principle, it is possible to “grow” an integrated circuit, a biomedical sensor, or a display.
To get a system to self-assemble from the bottom up, you have to address a few key issues: how the parts are made, how they are induced to recognize and bind to each other in the correct fashion, and how the assembly process can be controlled and streamlined. Chemical synthesis can readily produce a large number of nanoscale “parts” such as quantum dots or molecules that are designed to perform specific functions. And researchers can take advantage of specific covalent bonds or supramolecular bonds such as DNA hybridization or protein-inorganic surface interactions to program the self-assembly process.
Our group has investigated these methods as a way to produce hybrid organic-inorganic transistors and photonic waveguides. Solid-state microfabrication is another technique for producing parts for self-assembly. The parts are fabricated separately, released, and then induced to self-assemble. Our group has used this approach to construct high-performance silicon circuits on plastic.
This revolutionary manufacturing method offers many opportunities. Growing machines may not be as far-fetched as it once seemed.
Indeed. Both self-assembly and directed assembly as approaches to atomically-precise manufacturing will be covered at next month’s Productive Nanosystems Conference. —Christine