| Author | Hasan, Md. Mahadi |
| Call Number | AIT Thesis no.ISE-12-32 |
| Subject(s) | Membrane separation
|
| Note | A thesis submitted in partial fulfillment of the requirements for the Degree of Masters in Engineering In Mechatronics, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. ISE-12-32 |
| Abstract | Fabrication of microchannel is an expe nsive and complex process. It requires high - end lithographic techniques, precise environment maintenance and costly materials, which may not be affordable for small scale laboratories. Here a nonlithographic technique has been used in the first stage of t he study before adopting lithographic procedures in the second stage. A novel 3D microstructure has been fabricated with the help of Anodic aluminum oxide (AAO) membranes. An easy method has been adopted which does not require any multiple layer deposition procedures. In this method Al sample was punched in a way to give a continuous curved shape from both sides, followed by anodization and etching of Al. The behavior of AAO to AAO bonding has been utilized as when anodization takes place from both sides of Al simultaneously , the grown alumina (Al 2 O 3 ) attaches with each other at their barrier layers. The fabricated microchannel thickness was 75 μm with 37 μm thick membrane walls. Average diameter of nanopores in the walls was 50 nm. This low cost nanoporous microchannel is expected to have potentials in sensors, molecular separation and biomedical related applications. In the second stage of the study a series of straight microchannels have been fabricated using standard lithographic techniques. In this metho d a thinner AAO membrane has been integrated on the top of channels as because in the applications where very thin membrane and larger surface area is necessary AAO can play a significant role. But to maintain the thickness of AAO membrane is a challenging task since when thickness is reduced the mechanical property or rigidity of the membrane abridged such that it can’t sustain anymore due to inherent fragile property of AAO. On the other hand thicker membrane causes hindrance during filtration which resul ts reduced performance of the filtration. To solve this problem Microchannels have been fabricated with the aim of performing dual actions. The channel pillars will support the membrane as well as flow away the filtered (unwanted) material. The fabricated membrane thickness wa s 4 μm. The pore diameter remains same as fabricated in first stage. 99.56 % pure Aluminum and Glass was used for fabrication of membrane and substrate successively. Both fabricated structures have the potential to be used where lager filtration area is nece ssary. Thinner membrane can save time of filtration which is very important in medical view point. |
| Year | 2012 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. ISE-12-32 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Industrial Systems Engineering (DISE) |
| Academic Program/FoS | Industrial Systems Engineering (ISE) |
| Chairperson(s) | Afzulpurkar, Nitin V. |
| Examination Committee(s) | Bohez, Erik L.J.; Chumnarn Punyasai |
| Scholarship Donor(s) | HM King Scholarship |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2012 |