George Lauro, board member of Illuminex tells us, "We are a 10-person company developing a nanowire material/process platform targeting Battery Anode, Thermal and Solar/PV markets. Illuminex' unique Si nanowire anode structure is demonstrating very significant advantages over graphite or other anode materials. We are sampling silicon nanowire anode material for Lithium Ion batteries, nanowire PV arrays and are generating revenue from nanowire material sales, development projects with commercial partners and have closed several Federal/State Grants. The Company is profitable, but is seeking growth financing and corporate partnerships."
Illuminex was founded by MIT PhD nanomaterial scientists and based in Lancaster, Philadelphia USA. It is commercializing platform nanowire array process technology enabling innovative functional, smart, nano-structured materials. We believe Illuminex has world-leading nanowire manufacturing capabilities in terms of breadth of materials, substrates, shapes and structures.
Illuminex' processes produce high aspect, vertically-aligned, free-standing, uniform nanowire arrays on a variety of substrate materials. These nanowires are attached mechanically and electrically to the underlying substrate to form a miniature "bristle" network. Illuminex can engineer nanowires with diameters of 20-900 nm, lengths of 10nm-200microns, and a center- to-center spacing between neighbouring nanowires 1 to 5 times their diameter. Illuminex can produce a variety of nanowire arrays tailored for numerous applications:
- Photovoltaic panels and threads: Silicon p-n junction diode nanowires on glass or emanating about the periphery of a 200 micron diameter thread for PV
- Copper Core-Silicon Shell nanowires for Lithium Ion battery anodes
- Copper nanowire on Copper sheet for heat pipes
- Silver nanowires on ITO coated glass for biosensors
Manufacturing process is based on a multifaceted use of Aluminum and controlled utilization of inherent self-organizational materials properties. This Novel "bottom-up" production process yields far more rapid nanowire production at lower cost than competing processes. Illuminex uses mature electro-chemical equipment and processes. Plating, anodizing, polishing and standard wet chemistry equipment is readily adapted to Illuminex processes. Most other nanowire developers use exotic and expensive research tools like reactive ion etching and ion milling processes.
Products include:
Lithium Ion Battery anodes: Illuminex Copper Core- Silicon Shell nanowires are under evaluation by Lithium Ion battery suppliers for battery anodes. Nanowires deliver high energy density with very low fade rates using large scale low cost manufacturing processes. Graphite is the commonly used anode in Lithium Ion batteries, but has limited charge capacity of 372 mAh/g. Silicon is an attractive anode material because it has a low discharge potential and the highest known theoretical charge capacity (4,200 mAh g-1). However bulk silicon expands (up to 400%) as it reacts with lithium, and disintegrates from the stress. This has prevented the successful implementation of silicon in Lithium Ion batteries. Illuminex Cu core-Si shell nanowires expand homogeneously, minimizing stress, and have ductile behaviour which can accommodate any existing stress
Heatpipe and thermal interface materials: Currently in small volume revenue. Illuminex nanowire arrays create a heatpipe wick material to replace conventional sintered copper powder. Illuminex nanowire wicks have 30% lower thermal resistance than sintered copper wicks and they perform well to input heat fluxes exceeding 350 W/cm3, where sintered powder heatpipes fail catastrophically. Modelling shows that longer term, Illuminex nanowire wicks could enable heatpipes with 5X improvement over conventional sintered copper heatpipes at comparable cost. Illuminex is targeting heatpipe markets for servers/PC's, microprocessors, Military and Industrial as well as broader markets for Thermal Interface Material.
PV Cells: Illuminex is prototyping, at a small scale, nanowire PV cells based on a dense array of Silicon Diode nanowires- pillar shaped Silicon p-n junction diodes on glass sheets. The PV nanowire material has a theoretical efficiency of 35%, greater than Bulk Crystalline Si (20%). Nanowire PV based cells use 1/100 the amount of silicon per PV cell area as silicon based cells and hence are potentially much lower cost. They can fabricate the Silicon diode nanowires on glass, metal, threads or virtually any surface that can be coated. Nanowire PV can be made on flexible substrates such as flexible polymers.
PV Threads: Illuminex is producing pillar-shaped Silicon p-n junction diode nanowires emanating about the periphery of a 200 micron diameter thread for PV. The Company is developing processes to weave these photovoltaic threads to create PV textiles, and with other smart textile components; super-capacitors for storage and LED's for display.
For more contact george.lauro@alteoncapital.com
Top image of silicon nanowires source Illuminex
For more read : Energy Harvesting and Storage for Electronic Devices 2009-2019
