Research

The group is divided up in to three main research thrusts:

Carbon Mechanics

 RF-NEMS are important for both fundamental research (e.g. pushing the limits of mass, charge, magnetic sensing) and technology (e.g.transceivers for wireless communications, biosensing, etc). Graphene NEMS represent the ultimate limit of such devices. In our group, we develop novel fabrication techniques to create large arrays of graphene NEMS for large-scale on-chip nanomechanical signal processing. We develop novel readout techniques to overcome the challenges associated with the electrical detection of small displacements (of the level of a few angstroms) at high frequencies and apply these to develop novel devices such as tunable filters, voltage-controlled oscillators and other nanomechanical radio frequency integrated circuits (RFICs). We are also interested in using mechanical motion to probe the fundamental physics of graphene e.g. in the quantum Hall regime.


Carbon Electronics

 Using mechanical techniques to manipulate and transfer materials at the nano-scale, we fabricate layered heterostructures utilizing single-layer graphene and carbon nanotubes as building blocks.  This allows us to better isolate and study the intrinsic electronic properties of 2D and 1D systems (e.g. quantum Hall effect and Luttinger liquid behaviour, respectively) while also enabling us to engineer new layered, meta-materials with new device functionality (e.g high performance field effect transistors for high frequency analog applications).We are also interested in studying bilayer graphene where the existence of a dynamically variable bandgap, a unique feature not found in conventional semiconductors, allows the possibility of realizing tunable digitial devices and novel opto-electronic applications.  Finally, we maintain a continued effort on realizing scalability in graphene devices through the development of improved wafer-scale growth techniques. 

 


Nano-Bio Interfaces

 

Transparent and conducting films are used in modern technologies like video displays, solar cells, lasers, optical communication devices and solid state lighting. Carbon nanotube films are also a class of conducting materials that are gaining a lot of attention due to their extraordinary optical transparency as well as low sheet resistance. These conducting nanotube films are a potential candidate for usage in dye sensitized solar cells as well as fuel cells, where they can be used both as conducting electrode materials as well as catalyst support for enhacing the electrochemical reaction.

102 SW Mudd, Mail Code 4703, 500 W 120th Street, New York , NY 10027    212-854-6644                
©2014 Columbia University