Particles magnetically 'click' to form superstructures
Tuesday, April 10, 2012 - 11:10
in Physics & Chemistry
(Phys.org) -- Geomag, the popular children's toy, contains small metal spheres that can be magnetically connected with a click to build a variety of towers, bridges, and sculptures. In a new study, scientists have done something similar on the microscale: they've created a new class of spherical colloids that have tiny magnetic patches embedded beneath their surfaces. In the absence of a magnetic field, the colloidal particles can spontaneously form clusters of controlled size and shape. With the application of an external magnetic field, the clusters can unbind and change their geometry, allowing the structures to reconfigure themselves independent of the chemical conditions of the environment.