| Popis: |
Nanofabrication of biomedical devices is a developing field. Traditional methods used to create these devices work well, but suffer the drawbacks of being expensive and only capable of low throughput production. Novel methods to fabricate nano-scale features are being explored, with technologies that can create such features on large surface areas and minimal equipment being the most desirable. DNA combing and imprinting (DCI) is such a technique. DCI is a low-cost, non-cleanroom alternative to technologies such as e-beam lithography and is capable of creating polymeric biomedical devices presenting embedded nano-channels on surfaces up to 1cm2 in area. This is done by using DNA as a physical scaffold around which the nano-channels are molded. DCI requires minimal equipment and is mostly a manual fabrication technique. Drawbacks of this method include low yield and large variation. For this reason, a more robust process is desired, with the goal being a fully automated production design. This required a re-design of the mechanism of DNA combing that has been termed dip-combing. This new method is able to consistently create DNA nano-wires on the micro-patterned surfaces with defect rates lower than 1%. A hands-off system for the DNA imprinting has also been designed in order to minimize human error when handling the fragile nano-wires. Originally, bio-chips fabricated using DCI were made of ethylene glycol dimethacrylate (EGDMA), but this proved to be brittle and shortened the life of the device. This led to the study of alternative materials that would be more robust, but still behave similarly.Many uses for devices containing nano-channels exist such as sensing, nano-manipulation, and drug delivery. Micro-well/nano-channel electrophoresis is another technology that would utilize large arrays of regular nano-channels. Using devices created by the DCI process, this technique, much like gel electrophoresis, separates biomolecules based on size and charge by forcing the sample to electrokinetically flow through many nano-channels in succession. It is hoped that this new method will be able to allow for the separation and collection of miRNA samples from single cells that can then be used for further analysis. The fabrication of such devices is studied here as well as the experimental setup. The feasibility of flowing material through successive nano-channels must be explored to determine if this technology has the potential to create a novel bio-separation method using a device fabricated by the DCI process. |
