Method for orientation of liquid crystals in micro/nano region on basis of laser direct writing and system thereof
The method for orientation of liquid crystals in a micro/nano region on the basis of laser direct writing and a system thereof includes a laser direct writing system employed to build a micro/nano structure. Liquid crystal molecules in a micro/nano structural region perform self-orientation; and the orientation of liquid crystals is generated by fine structures on side walls of polymer strips which form the micro/nano structure. The dimension of the micro/nano region varies from the micrometer magnitude to the nanometer magnitude exceeding the diffraction limit. The orientating direction can be adjusted and controlled in the micro/nano region, which is favorable for the miniaturization of the liquid crystal display devices and the orientation of the complicated three-dimensional liquid crystal structure.
1. A method for orientation of liquid crystals, the method comprising the steps of:
preparing a sample being comprised of a substrate with a substrate plane and polymerizable organics spin-coated on said substrate;
building a micro/nano structure,
wherein said step of building said micro/nano structure comprises the steps of:
laser direct writing said sample,
wherein said step of laser direct writing comprises:
continuously changing a position of a laser spot of a laser relative to said polymerizable organics; and
polymerizing a portion of said polymerizable organics consistent with movement trajectory of said laser spot so as to form a plurality of polymer strips arranged in parallel to each other in one direction and perpendicular to said substrate plane, each polymer strip having side walls, and so as to form polymerized and unpolymerized portions on said substrate; and
removing said unpolymerized portions so as to form said micro/nano structure with fine structures on respective side walls of said polymer strips,
wherein height of each polymer strip is greater than 2.0 microns; and
injecting liquid crystals into said micro/nano structure with fine structures so as to perform self-orientation of said liquid crystals parallel to said one direction of said polymer strips, said liquid crystals separating into a plurality of liquid crystal portions between adjacent polymer strips, each liquid crystal portion being separate from each other.
2. The method for the orientation of liquid crystals, according to claim 1 , wherein the step of laser direct writing is comprised of a single photon laser direct writing.
3. The method for the orientation of liquid crystals, according to claim 2 , wherein said fine structures on respective side walls of said polymer strips are formed by single incident light.
4. The method for the orientation of liquid crystals, according to claim 1 , wherein the step of said laser direct writing is comprised of multi-photon laser direct writing.
5. The method for the orientation of liquid crystals, according to claim 1 , wherein said liquid crystals are selected from a group consisting of: orientable nematic liquid crystals, cholesteric liquid crystals and chiral liquid crystals.
6. The method for the orientation of liquid crystals, according to claim 1 , wherein said micro/nano structure is selected from a group consisting of: a one-dimensional structure, a two-dimensional structure, and a three-dimensional structure.