nanogripper

Text Box: Hands-on nanotechnology: towards a nanorobotic assembly line (contact Peter Boggild, boggild@mic.dtu.dk for more information)
Robots are commonplace in industry, assembling everything from cars to electronics day after day, and it has long been a dream for nanotechnologists that robots could one day be used in a similar way to produce nanodevices. A nanogripper controlled by a nanorobotic arm has now picked up a carbon nanofibre and fixed it onto the tip of an atomic force microscope cantilever. A group of researchers from the Technical University of Denmark (DTU) and University of Oldenburg (UO) have now shown the feasibility of "pick-and-place" assembly of a working device using a silicon microgripper - a robotic “hand” some 10000 times smaller than a human hand. They managed to break off a sturdy carbon nanofibre, and position it at the pyramidal tip of an atomic force cantilever. After fixing the nanofibre with a type of nanoglue, the long slender tip was used to probe deep trenches, performing much better than standard atomic force cantilevers. Associate professor Peter Bøggild from DTU considers this a great leap forward:

"Nanomanipulation has been around for a few decades, but so far mostly used for basic science and for showing what the future might hold. On the road to the first assembly line inside an electron microscope, we have now demonstrated the basic construction of a working device using a small silicon gripper. Yet, to turn this into an automatic and competitive process, we must continue to push the limits for speed, precision and reproducibility even further.” How does the gripper work? Special parts of the gripper are heated up with an electrical current, and the thermal expansion is converted into a powerful gripping action of the micron-separated jaws. The gripper, developed by researchers at DTU, is a part of an advanced nanorobotic system with integrated 3D electron microscopy and image recognition, constructed by Research Associate Volkmar Eicchorn and colleagues at University of Oldenburg. Prof. Sergej Fatikow (OU) is confident that such nanorobotic systems are the most promising approach towards rapid prototyping of future nanodevices. So far carbon nanotubes and nanofibres with diameters down to 100 nm have been manipulated, but in two years smaller tools will manipulate 10-20 nm wide wires and tubes. There are many problems to solve to reach this goal, however. On the nanoscale, 3D manipulation is painstakingly difficult: the robotic arms must work with extreme precision, and real-time imaging of nanostructures is just about possible. Creating the tiny “hands” for the robot is a great challenge: the fingers must be thin and flexible, and yet have sufficient strength to break off nanotubes from their initial position. Finally, the powerful surface forces on the nanoscale make all objects sticky.
The work has been done in the framework of two European projects, NANOHAND and NANORAC, gathering the top European laboratories and hi-tech companies in robotics, nanomanipulation, microscopy and nanofabrication to realise a first shot at a nanomanufacturing assembly line before 2009.