| Regional Biophysics Meeting 2005, March 16-20, Zreče, Slovenia | [NanoBioTech] |
Modern biological investigations demand methods where a large number of tests can be performed on small amounts of material in a short time. The natural answer to these problems is miniaturization: lab-on-a-chip technology. We introduce a method promising for the construction of complex micromechanical devices, where mechanical, optical and electrical components can be readily integrated. The method is based on the photopolymerisation of light curing resins by focussed laser light. By moving the focus along a predetermined trajectory, objects of arbitrary shape can be built. The force exerted by focused laser light of the order of 10 mW intensity upon micrometer-size objects has also the right magnitude to move them, i.e. the mechanical systems can be activated by light, too. We have built complex micromechanical systems by the photopolymerisation of light curing resins. The technology demonstrator machines have a total size of several microns, they consist of static and moving parts built together as an integrated unit. They are driven by rotors that are rotated by light. As an illustration of the power of the technique a method is described by which it is possible to apply and measure torque directly on single biological macromolecules. Single DNA molecules and actin filaments are pulled and twisted by laser tweezers. The torque is constantly monitored during twisting. The torsional elasticity is directly determined and the dynamics of twisting is studied.
Email: pali@nucleus.szbk.u-szeged.hu
Address: Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences Szeged, P.O.Box. 521 H-6701 Hungary