A variety of research projects and opportunities in nanotechnology exist in the Department of Electrical Engineering and Computer Science at the University of Wisconsin-Milwaukee.
Nano-Technology Research Laboratory
A nanometer stands for one billionth of a meter, the scale at which a new technological revolution is currently happening. Nanotechnology has its primary goal of manipulating matter on atomic and molecular scales as a pathway to enable novel nano-metric materials and interfaces for applications far beyond electronics. By hierarchically assembling single nano-components into larger length scale architectures, one can now engineer hybrid opto-electro-mechanical devices and systems that have been previously unavailable.
The devices featuring a size of several nanometers or less are also attractive for interfacing with biological systems and machines. This will potentially open new horizons in bio-medical research and provide additional insights into cell functioning and structuring on the molecular level.
Currently, the mission of the laboratory is to address some of the challenges in nanoscale research, including controlled synthesis of low-dimensional structures and interfaces (based on the use of alumina templates in combination with CVD and MBE growth techniques), investigation of their novel electronic and device related characteristics, and engineering of multifunctional nano-opto-electronic devices and bio-material interfaces.
- Chemical Vapor Deposition and the effects of in-situ doping in crystalline Cd- and Zn- based one-dimensional nanostructures
- Carbon Nanotubes for Opto-Electronic Device and Biological Applications
- Opto-electronic and photoconduction effects in nano-scale semiconductors and oxides
- Self-assembly techniques for semiconductor processing and nano-device engineering
The laboratory is currently equipped with many state-of-the art instruments, including Horriba Jobin Yvon PL System with 2x grating excitation and emission spectrometers, single photon counting PMT and InGaAs liquid nitrogen cooled detectors featuring attached confocal Olympus Microscope with 15-x UV objective; Stanford-Research Digital Lock-In Amplifier, Janis Cryostat (T-range: 10-600 0K), Micromanipulator Probe Station with attached Mitutoyo Research Grade Microscope (magnifications 100x, 200x and 500x ), Bruker micro-FTIR system; Keithley Nanovoltmeter 2182A , Keithley DC-AC current sources 6221 and 236; 2 CVD reactors and an electrochemical processing system, and multiple instruments for bio-chemical processing and measurements.
Current funding is provided by NSF/ UWM.
Nanoelectromagnetic research at UWM focuses on the theory and simulation of the interaction of electromagnetic waves with nanostructures. The nanostructures of principal interest are carbon nanotubes and graphene, and related objects such as plasmonic nanostructures.
A carbon nanotube is a hollow cylinder with walls made of a single layer of carbon atoms. Carbon nanotubes typically have radius values of a few nanometers and lengths (so far) up to centimeters. Multi-wall carbon nanotubes are also very common.
Carbon nanotubes are held together by carbon-carbon bonds, and thus they exhibit extraordinary strength. In fact, carbon nanotubes are many times stronger than steel. They also have very high thermal conductivity and stiffness, and interesting electrical properties. They can be either metallic or semiconducting, and they can carry very high current densities (much higher than typical metals) without melting.
Currently, we are investigating arrays of carbon nanotubes for antenna applications, funded by the U.S. ARMY. This includes electromagnetic scattering from carbon nanotubes, and transmitting and receiving properties of nanotubes and nanotube arrays.
We are also investigating electromagnetic aspects of graphene, which is a planar atomic layer of carbon atoms bonded in a hexagonal structure. Graphene is the two-dimensional version of graphite and is related to carbon nanotubes in that a single-wall carbon nanotube can be thought of as a graphene sheet rolled into a tube. Graphene is a very promising material in emerging nanoelectronic applications, and preliminary work indicates that it can be used to guide electromagnetic energy in a somewhat controlled fashion. Our research has concentrated on the control of electromagnetic surface waves by applied bias fields