Research in the Cha laboratory is focused on using biological and chemical approaches to assemble nanoscale materials, such as metal and semiconductor nanoparticles, nanorods, nanowires, and single walled carbon nanotubes. Due to their unique electronic, optical, and mechanical properties, nanoscale materials have been heavily explored for applications that range from medicine to electronics to energy. However, their sub-20nm dimensions have led to difficulties in directing their placement, orientation, or assembly into functional architectures. For example, a bottom-up approach that can direct the placement of nanoscale materials on lithographically defined surfaces is key to many electronics applications. For medical imaging and therapy, it is important to engineer ways to fabricate 3-dimensional biocompatible nanoscale assemblies, such as micelles or liposomes that can also release payloads.
Fundamental research in the Cha group is focused on the design and use of chemistry and engineering to synthesize and create well-defined organic-inorganic systems from nanoscale material building blocks. Because biological molecules, such as peptides, DNA, and proteins, provide significant capabilities for the assembly of nanoscale materials, a significant portion of the research centers around interfacing biological systems with nanoscale objects and using biomolecular interactions to drive the assembly. Specific applications include engineering nanoparticle-peptide systems for in vitro and in vivo detection, synthesizing inorganic-polypeptide systems into 2- and 3-dimensional arrays, and using DNA based bottom-up approaches to build parallel arrays of nanoelectronic devices.