Childres I.,Purdue University |
Jauregui L.A.,Purdue University |
Foxe M.,Purdue University |
Foxe M.,Pennsylvania State University |
And 6 more authors.
Applied Physics Letters | Year: 2010
Electron beam exposure is a commonly used tool for fabricating and imaging graphene-based devices. Here, we present a study of the effects of electron-beam irradiation on the electronic transport properties of graphene and the operation of graphene field-effect transistors (GFETs). Exposure to a 30 keV electron-beam caused negative shifts in the charge-neutral point (CNP) of the GFET, interpreted as due to n-doping in the graphene from the interaction of the energetic electron beam with the substrate. The shift in the CNP is substantially reduced for suspended graphene devices. The electron beam is seen to also decrease the carrier mobilities and minimum conductivity, indicating defects created in the graphene. The findings are valuable for understanding the effects of radiation damage on graphene and for the development of radiation-hard graphene-based electronics. © 2010 American Institute of Physics. Source
Agency: National Science Foundation | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 200.00K | Year: 2010
This Small Business Innovation Research Phase I project is to demonstrate the feasibility of batch fabricating high-aspect ratio atomic force microscopy (AFM) probes. These probes have excellent mechanical and electrical properties and are customizable to a wide range of applications and substrates. Currently each probe is individually fabricated by dipping a silver-coated probe into melted gallium at room temperature, resulting in the self-assembly of a long, constant-diameter metal nanoneedle on the probe tip. Current production throughput is only five probes per hour. Because of their unique form and function there is a growing demand for these probes which can only be met if they are fabricated in parallel. In Phase I, a batch process will be developed, with the goal of moderate yield (25%) over a 1 cm square area. One innovative aspect of the project is the use of a gallium coated substrate that has an elastomeric underlayer to provide a degree of self-alignment that ensures intimate contact of the thick gallium film layer with surfaces that are not perfectly flat. The extension of this concept - in future studies - to the patterning of arrays of freestanding nanoneedles over curved and multilevel substrates appears reasonable. Based on the attainment of adequate yields in Phase I, Phase II will focus on the development of a semi-automated tool for wafer-scale growth of probes. The broader impact/commercial potential of this project is a dramatically increased commercial viability of a new kind of specialized AFM probe. The total market for AFM probes is $385 million, of which up to $100 million is addressable, if such probes can be fabricated in larger quantities. Since the launch of this technology in late 2008, customer feedback has been overwhelmingly positive. Current customers of these probes have made it clear that this new probe technology represents an enabling tool which will help advance and accelerate the pace of research and discovery in areas including nanomanipulation, biophysical probing, nanomechanics, nanoelectronics and metrology. The long range economic and societal impact will be a new manufactured product which will help to maintain U.S. leadership in nanotechnology and create high-paying technical jobs for scientists and engineers in Kentucky, a state where such opportunities have traditionally been extremely limited.
NaugaNeedles LLC | Date: 2011-11-22
In one embodiment, the present invention provides the description of an inexpensive and disposable handheld device for detecting Circulating tumor cells (CTC) in blood called a handheld CTC detector (HCTCD). The HCTCD is capable of detecting less than
Agency: NSF | Branch: Standard Grant | Program: | Phase: | Award Amount: 892.00K | Year: 2011
This Small Business Innovation Research (SBIR) Phase II project aims to develop a low-cost manufacturing process to produce conductive and high-aspect-ratio probes for atomic force microscopy (AFM). A new fabrication tool with high-precision alignment and in-situ process monitoring sensors will be designed and constructed. The probes (so-called NeedleProbes) will be fabricated in a batch process that can pattern an entire wafer of conventional AFM probes with freestanding metal alloy nanowire tips.
The broader/commercial impacts of this project will be the potential to provide affordable, conductive and high-aspect-ratio AFM probes that would be well suited in biology for cell scanning and probing, and materials science for imaging of ultra-high-aspect-ratio structures, and electronic measurement of nanostructures. The current fabrication method of AFM probes is a serial process that produces approximately five probes per hour. The advancement in this project toward batch fabrication is expected to extend far beyond the current fabrication method and result in a price reduction of the probes by a factor of 5.
NaugaNeedles LLC | Date: 2011-08-22
The present invention provides a description for an instrument for creating arrays of metal nanostructures allows on various substrates at the wafer scale. Embodiment methods permit for the formation of individual and arrays of metal alloys of nanostructures by bringing an array of liquid metal droplets droplet in contact with an array of metal patterns by using high precision manipulation mechanism. Top view and side view optical lenses are used to observe the manipulation process and also allow for aligning the metal droplets with film of solid metal patterns. As one example, this instrument is capable of pattering high aspect ratio nanostructures such as silver-gallium (Ag