Microtransfer Molding - Marissa Burgess, Ruptanu Banerjee, Vaishali Malik: Difference between revisions
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== Limitations == | == Limitations == | ||
Stamp or mold deformation is one of the main challenges that can be encountered during microtransfer molding. For example, the precursors used to create ceramics are generally liquid-based sol or colloidal suspensions, largely consisting of organic and aqueous material that must be removed when the liquid is converted into a solid. During the drying and sintering process, the thin film may diverge from the original shape from shrinking.[2] | Stamp or mold deformation is one of the main challenges that can be encountered during microtransfer molding. For example, the precursors used to create ceramics are generally liquid-based sol or colloidal suspensions, largely consisting of organic and aqueous material that must be removed when the liquid is converted into a solid. During the drying and sintering process, the thin film may diverge from the original shape from shrinking. [2] | ||
== Recent Advances == | == Recent Advances == | ||
Electrically modulated microtransfer molding is a newer technique closely related to microtransfer molding. The ability to create electrically modulated micropillar arrays over a large area has opened up new frontiers in surface engineering, biotechnology, and microfluidics. [ | Microtransfer molding holds great promise in the design of microfluidic devices. An example is the development of a chip for capillary electrophoresis separation. [3] | ||
Electrically modulated microtransfer molding is a newer technique closely related to microtransfer molding. The ability to create electrically modulated micropillar arrays over a large area has opened up new frontiers in surface engineering, biotechnology, and microfluidics. [4] | |||
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[2] Martin, C. R.; Aksay, I. A. Journal of Materials Research 2005, 20 (08), 1995–2003. | [2] Martin, C. R.; Aksay, I. A. Journal of Materials Research 2005, 20 (08), 1995–2003. | ||
[3] Li, X.; Tian, H.; Shao, J.; Ding, Y.; Liu, H. Langmuir 2013, 29 (5), 1351–1355 | [3] Duffy et al., Anal. Chem., 1998, 70, 4974. | ||
[4] Li, X.; Tian, H.; Shao, J.; Ding, Y.; Liu, H. Langmuir 2013, 29 (5), 1351–1355 |
Revision as of 21:42, 17 February 2017
Mictrotransfer molding (μTM) is a form of soft lithography - a set of pattern transfer techniques that employs a patterned elastomer as a stamp, mask, or mold.
The most commonly used elastic polymer in microtransfer molding is polydimethylsiloxane (PDMS). PDMS generally comes in two components including the prepolymer and the curing agent. The hardening of PDMS is achieved through the cross-linking of its polymer chains via thermal curing.
General Procedure
In microtransfer molding, a PDMS-based mold called a "stamp" is utilized. The PDMS stamp contains recessed regions, or microchannels, that are manually filled with prepolymer or ceramic precursor. The PDMS stamp, filled with prepolymer, is then inverted and brought into contact with the substrate. Next, the polymer is cured, and the PDMS stamp is peeled away. This results in polymer microstructures on the substrate arranged based on the design of the channels in the PDMS stamp.
Advantages
Several significant benefits can be noted regarding the process of microtransfer molding. The entire process is rapid with, the capability of replicating microstructures in five minutes or less. Both isolated and interconnected structures can be generated as well. In contrast to other patterning techniques, microtransfer molding can form structures on contoured surfaces in addition to flat surfaces. This trait is necessary for the microfabrication of 3-Dimensional structures, as the polymer can be deposited and cured layer by layer into the desired 3-D shape. [1]
Microtransfer molding also has low capital and operating costs, and it is cheap to create which results in the ability to rapidly prototype.
Limitations
Stamp or mold deformation is one of the main challenges that can be encountered during microtransfer molding. For example, the precursors used to create ceramics are generally liquid-based sol or colloidal suspensions, largely consisting of organic and aqueous material that must be removed when the liquid is converted into a solid. During the drying and sintering process, the thin film may diverge from the original shape from shrinking. [2]
Recent Advances
Microtransfer molding holds great promise in the design of microfluidic devices. An example is the development of a chip for capillary electrophoresis separation. [3]
Electrically modulated microtransfer molding is a newer technique closely related to microtransfer molding. The ability to create electrically modulated micropillar arrays over a large area has opened up new frontiers in surface engineering, biotechnology, and microfluidics. [4]
References
[1] Zhao, X.-M.; Xia, Y.; Whitesides, G. M. Advanced Materials 1996, 8 (10), 837–840.
[2] Martin, C. R.; Aksay, I. A. Journal of Materials Research 2005, 20 (08), 1995–2003.
[3] Duffy et al., Anal. Chem., 1998, 70, 4974.
[4] Li, X.; Tian, H.; Shao, J.; Ding, Y.; Liu, H. Langmuir 2013, 29 (5), 1351–1355