Imagine a computer chip that can assemble itself. According to Eric M Furst, professor of chemical and biomolecular engineering at the University of Delaware, engineers and scientists are closer to making this and other scalable forms of nanotechnology a reality as a result of new milestones in using nanoparticles as building blocks in functional materials.
Furst and his postdoctoral researchers, James Swan and Paula Vasquez, along with colleagues at Nasa, the European Space Agency, Zin Technologies and Lehigh University, report the finding in an article in the Proceedings of the National Academies of Science (PNAS) online edition.
Titled “Multi-scale kinetics of a field-directed colloidal phase transition”, the article details how the research team’s exploration of colloids, microscopic particles that are mere hundredths the diameter of a human hair, to better understand how nano-“building blocks” can be directed to “self-assemble” into specific structures.
The research team studied paramagnetic colloids while periodically applying an external magnetic field at different intervals. With just the right frequency and field strength, the team was able to watch the particles transition from a random, solid-like material into highly organised crystalline structures or lattices.
According to Furst, no one before has ever witnessed this guided “phase separation” of particles. “This development is exciting because it provides insight into how researchers can build organised structures, crystals of particles, using directing fields – and it may prompt new discoveries into how we can get materials to organise themselves.”
The work could potentially prove important in manufacturing, where the ability to pre-program and direct the self-assembly of functional materials is highly desirable.