Dr. An’s research lies in the following general areas: processing-structure-property relationships of ceramic materials, microfabrication of ceramics for extreme environmental MEMS, nano- and microstructure design for improving properties of ceramics and their composites and mechanical property characterization with indentation techniques.

In particular, Dr. An’s recent research focuses on polymer-derived ceramics (PDC) synthesized by thermal decomposition of polymer precursors at 400-1000 oC. This new class of materials, based on amorphous alloys of silicon, carbon, boron and nitrogen, exhibits excellent mechanical and thermal properties up to 1800 oC, promising for ultrahigh temperature applications. The nanostructures and composites, thereby the properties, of PDCs can be tailored by modifying the chemistry of the precursors. This offers a unique opportunity to manipulate materials at atomic level to achieve improved properties and multifunctional behavior. The chemical route is also leading to cost-efficient and flexible manufacturing techniques for the fabrication of ceramic components with these interesting materials. Dr. An’s research group focuses on understanding nanostructure-properties relationships, designing novel multifunctional materials and synthesizing ceramic composites such as carbon nanotube reinforced PDC.

Dr. An’s group also conducts research on developing micro-fabrication technologies for ceramic-based MEMS. The unique processing and properties of PDCs make the materials suitable for ceramic MEMS applications. Dr. An is developing both micro-stereolithography and micro-injection molding techniques for the fabrication of MEMS components/devices with 3D complex structures. The picture below is a ceramic micro-gear made from micro-casting technique.

Dr. An is also working on nano-phased ceramic metal matrix composites. The research focuses on designing nano/microstructures and interfacial properties to improve mechanical properties, such as yield strength, creep and fatigue resistance.

Selected Publications

L. Liew, W. Zhang, L. An, S. Shah, R. Lou, Y. Liu, T. Cross, K. Anseth, V. Bright and R. Raj, “Ceramic MEMS – New Materials, Innovative Processing and Futuristic Applications,” American Ceramic Society Bulletin, 80(5), 25-30 (2001).

P.A. Ramakrishnan, Y.T. Wang, D. Balzar, L. An, C. Haluschka, R. Riedel and A. Herman, “Si-B-C-N Ceramics: A New Class of High Temperature, Dopable Electronic Materials,” APL, 78[20], 3076-78 (2001).

R. Raj, L. An, S. Shah, R. Riedel, C. Fasel and H.-J. Kleebe “Oxidation Kinetics of An Amorphous Silicon Carbonitride Ceramics,” J. Am. Ceram. Soc., 84 (8), 1803-1810 (2001).

L. An, “Indentation Fatigue in Random and Textured Alumina Composites,” J. Am. Ceram. Soc., 82, 178-82 (1999).

L. An, R. Riedel, C. Konetachny, H.J. Kleebe and R. Raj, “Newtonian Viscosity of Amorphous Silicon Carbonitride at High Temperature,” J. Am. Ceram. Soc., 81, 1349-52 (1998).

Polymer-derived SiCN ceramic micro-gear of 200 mm diameter and
40 mm thickness, fabricated with the micro-casting technique