Jonah Erlebacher Ph.D.
Professor Erlebacher is interested in the manufacture and characterization of nanostructured materials. He shares a vision that materials with nanoscale features, and new methods to make these materials, represent a critical challenge for 21st century technology. Successful progress in Erlebacher's research will have ramifications for both energy conversion and information technology.Ongoing projects include:
Morphological Control and Applications of Nanoporous Gold (NSF CAREER):
Selective dissolution of silver from silver/gold films produces a remarkable material -- nanoporous gold (NPG). NPG possesses open porosity with ligament width/separation as small as 5 nm! NPG has the ultra-high surface area typical of nanoparticles, but is electrically and structurally continuous. Erlebacher's group has developed methods to coat NPG with uniform monolayers of catalytic elements such as Pt. In this way, the high surface area of NPG becomes catalytic in an economical manner. They are using these composite nanostructures to make fuel cells electrodes, study the properties of 3-D collections of magnetic nanoparticles, and develop novel sensor architectures.
Nanoscale Self-Organization (DOE/BES): Typically, materials that have very small features are also very kinetically active compared to their behavior in bulk. Erlebacher takes advantage of this to employ self-organization and pattern formation as a means to create novel nanostructures. He is has examined methods to create nanoripples on semiconductor surfaces by ion-beam etching. These kinds of morphologies form spontaneously as the result of non-equilibrium competition between kinetic processes of roughening and smoothening, and can be made by one-step processing techniques. Such self-organized patterns on silicon wafer substrates may be transferred to vapor deposited films.
Nanoscale Engineering of Bilaterally Accessible Biomembrane Mimics (NSF/NIRT): In this highly interdisciplinary effort, Erlebacher's group and collaborators are developing a "molecular toolkit" by which combinations of lipid bilayers, protein sheets (S-layers), secondary cell wall polymers are supported on nanoporous gold substrates in order to create biomolecular structures that mimic the structure of cell walls. Because the substrate is porous and conductive, such biomembrane mimics will create new opportunities for studying transport through cell walls, as well as new architectures for biosensing.
The experimental methods used in Professor Erlebacher's research include wet-chemical acid etching, and also vapor deposition and ion etching in ultra-high vacuum. Professor Erlebacher analyzes the formation kinetics of his nanostructures by a combination of electron microscopy, scanning probe microscopy, and in situ UV light scattering.
Erlebacher complements his experimental program with computer modeling. He has developed a general use kinetic Monte Carlo (KMC) which has been used to study morphological equilibration of roughened surfaces and nanoporosity formation during electrochemical dissolution. Current simulation projects include (a) integration of the KMC code into a multi-scale simulation model in order to study the interface between atom-level diffusion and larger scale mechanical behavior, and (b) integration of an off-lattice "fluid phase" into the crystallographic KMC code to model electrochemical deposition.
EducationPh.D. Applied Physics, Harvard University, 1999; B.S. Physics, Yale University, 1991
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