Current Research

    My research interest is in the design and synthesis of inorganic/bio-organic nanoscaled components that can self-assemble into 3-dimensional hierarchical structures with novel physical and chemical properties. Our strategy is to abstract the efficient designs from nature to guide the synthesis of self-assembled components of materials systems.

Our research goal is to advance the understanding of the self-assembly process in the bio-inorganic systems by determining the physical and chemical mechanisms by which important inhibitors or promoters control the nucleation, growth, aggregation, and phase transformations of materials assembled from asymmetric and/or symmetric components. The types of systems we are currently studying are nanospheres, nanowires, and icosahedral viruses.

For the icosahedral virus system, we are investigating the properties and assembly mechanism of these particles from small protein fragments into virus crystals. Specifically, we examine the effects of different solution compositions on the assembly of virus structures in solutions. We are also mapping the inter-viral potential energy surfaces in different solution compositions that lead to different virus assembled structures with force microscopy techniques. Comparison between the hierarchical structures made with different solution compositions and Monte Carlos simulation results of the model systems with the thermodynamic data from the energy landscape measurements are used to provide further insight of the assembly mechanisms.

Since device physics and properties of materials are known to change when the dimension of the device is reduced down to the nanometer scale, we are also applying the knowledge learnt from the self-assembly mechanism to engineer and characterize functional nanostructures for prototyping various kinds of analytical devices. The aims of these projects are to bridge the "gap" in the assembly of materials between the nanoscale (1-10nm), mesoscale (10nm - 1µm) and the micron scale systems for the fabrication of functional devices and systems.

In my research group, students gain experience in synthesizing low-dimensional materials such as semiconducting nanotubes and nanowires using liquid phase and chemical vapor deposition methods. They also learn diverse materials characterization skills such as atomic force microscopy, transmission electron microscopy and scanning electron microscopy. They do research in areas ranging from biomimetics through physical chemistry to materials science and analytical device fabrication.

Recent Publications

Chen, L., Cheung, C.L., Ashby, P.D., and Lieber, C.M,. "Single-walled carbon nanotube AFM probes: optimal imaging resolution of nanoclusters and biomolecules in ambient and fluid environments", Nano Lett. 4, 1725-1731 (2004).

Weeks, B.L., Cheung, C.L., and De Yoreo, J.J., "The creation of organic and biological nanostructures at surfaces using scanning probe nanolithography", In From Solid-Fluid Interfaces to Nanostructural Engineering; Plenum/Kluwer Academic Publisher: New York (2004); Vol. II, 281-302.

Cheung, C.L., Camarero, J.A., Woods, B.W., Lin, T., Johnson, J.E., and De Yoreo, J.J., "Fabrication of assembled virus nanostructures with chemoselective linkers by scanning probe nanolithography", J. Am. Chem. Soc. 125, 6848-6849 (2003).

Cheung, C.L., Kurtz, A., Park, H., and Lieber, C.M., "Diameter-controlled synthesis of carbon nanotubes", J. Phys. Chem. B 106, 2429-2433 (2002).

Schnitzler, G.R., Cheung, C.L., Hafner, J.H., Saurin, A.J., Kingston, R.E., and Lieber, C.M., "Direct imaging of human SWI/SNF-remodeled mono- and polynucleosomes by atomic force microscopy employing carbon nanotube tips", Mol. Cell Biol. 21, 8504-851 (2001).

Hafner, J.H., Cheung, C.L., Woolley, A.T., and Lieber, C.M., "Structural and functional imaging with carbon nanotube AFM probes", Progr. Biophys. Mol. Biol. 77, 73-110 (2001).

Ouyang, M., Huang, J., Cheung, C.L., and Lieber, C.M., "Energy gaps in "metallic" single-walled carbon nanotubes", Science 292, 702 (2001).

Hafner, J.H., Cheung, C.L., Oosterkamp, T., and Lieber, C.M., "High yield fabrication of individual single-walled nanotube probe tips for atomic force microscopy", J. Phys. Chem. B. 105, 743-46 (2001).