Imprinting Platforms for Nanomanufacturing of Silicon: 2.5D Capabilities, High-Thoughput and New Applications
Bruno P. Azeredo
Nano-Micro Manufacturing Lab University of Illinois, Urbana-Champaign
Thursday, February 4, 2016
Santan (SANTN) 220, Polytechnic campus [map]
High throughput-processes such as imprinting, extrusion, and machining have been critical in the development of mass manufacturing of mechanical parts. Ranging from the macroscale to the nanoscale, these platforms have traditionally relied upon high stress and/or high temperatures to shape materials. In this talk, I will discuss methods that rely solely on the catalysis of chemical reactions to selectively remove material. These methods are the underlying mechanism for processing critical nanomaterials such as silicon nanowires. Currently, key challenges prevent scalable and low-cost processing of nanostructured silicon such as high defect density, low-dimensionality in geometrical control and low-throughput. In my research, I developed a novel imprinting platform to directly pattern Porous Silicon and single-crystal Silicon that makes progress towards addressing these challenges. This platform offers new capabilities such as sub-20 nm resolution, centimeter-scale parallelization and 2.5D geometrical control. Further, it operates at room temperature and utilizes earth-abundant and low cost chemicals, all of which lower the processing costs of silicon-based nanomaterials. But, what can we do with these new capabilities? Nanostructured silicon is (a) the highest-capacity anode for lithium-ion batteries, (b) the best IR material for silicon photonics, bio-imagining systems and high-emissivity surfaces, (c) a compatible material for bio-integrated electronics and, finally, (d) the most promising earth-abundant candidate for thermoelectric energy harvesters. To bring these applications into commercial development, my research may help scale nanomanufacturing of silicon from micrograms to kilograms in an economical and sustainable fashion.
Bruno Azeredo is currently a PhD Candidate in the Nano-Micro Manufacturing Lab at the University of Illinois at Urbana-Champaign. He obtained his M.S. and B.S. in Theoretical and Applied Mechanics and Engineering Mechanics both at UIUC. During his PhD, he was recipient of the NSF Graduate Research Fellowship and the James O. Smith Outstanding Teaching Assistant Award. In his research, Bruno focuses on the use of self-assembly processes and electrochemical methods for scaling the production of nanostructured inorganic semiconductors such as Silicon. Bruno strives to provide manufacturing solutions that are large scale and economically viable for future technology transfer. He also is interested in research in the integration of STEM and Arts (music and dance) at the undergraduate and K-12 level.
Figure 1: Examples of 2.5D patterns imprinted onto silicon wafers via Metal-Assisted Chemical Imprinting (Mac-imprint): (top) schematics of imprinting process and (bottom) AFM image of parabolic microconcentrator accurately defined and used for focusing light to the diffraction limit.