Biomotor-based nanotransport system constructed by pick-and-place assembly of individual molecules

Despite the benefits of miniaturized devices, handling of tiny amount of molecules became a great challenge. Direct transport, similar to the one in intracellular transport, is a way to cope with the problem of transporting tiny amount of materials. Using motor proteins, i.e. kinesin, and the corresponding rail structures, i.e. microtubules, provides powerful building blocks for a nanotransport system. However, it is extremely difficult to construct a complex transport network to allow arbitrary design. Here, we have developed a MEMS-based molecular handling system for the pick-and-place assembly of individual microtubules. The technology enabled us to build a bio/MEMS hybrid system composed of multidirectional microtubule networks along which kinesin molecules move. Using MEMS tweezers to manipulate a single microtubule enables precise positioning and full control in functional orientation and stacking order. As a result, kinesin-coated beads can be transported along the route specifically assembled for them to follow. Direct transport of target molecules can be achieved by loading the beads with the molecules to carry. “Bottom-up” functionalities of biomaterials are incorporated with micro fluidic devices by the handling capabilities of the “top-down” approach.