Hongjie Dai's research lab at Stanford University

The research of Dai group interfaces with chemistry, physics, materials science and biophysics. We are interested in solid state and soft condensed materials that have well-defined atomic structures. Ongoing projects include developing new synthetic routes to ordered nanomaterial architectures; electrical, mechanical, electromechanical and electrochemical characterizations at the nanoscale; and probing the real-space structures and functions of biological molecules. Our work are in the areas of material chemistry, inorganic synthesis, solid state physics, electron transport and scanning probe microscopy.

A specific research program involves the development of new synthesis methods to obtain ordered carbon nanotube architectures on surfaces. These novel nanowire architectures are ideal model systems for addressing fundamental physics problems in low dimensions, and for future device applications. Our overall approach involves the combination of inorganic synthesis of mesoporous catalytic materials and chemical vapor deposition with microfabrication techniques. With the synthesized nanowire architectures, we are carrying out electrical and electromechanical measurements of individual nanotube molecular wires, aimed to understand the properties of quasi-one-dimensional solids, elucidating quantum mechanical effects in small systems, and explore their applications in future miniaturized devices.

Another project involves using scanning probe microscopy techniques to probe the structural properties of biological macromolecules, and elucidate the interactions between individual molecular pairs. Our approach involves the development of atomic force microscopy probes that are tipped by individual nanotubes that are as small as ten angstroms in diameter. Such a molecular tip should allow structural imaging of biological systems with unprecedented resolution and sensitivity. We are also interested in electrochemical studies of biological systems using chemically functionalized nanotube electrodes.