Argonne National Laboratory is managed by The University of Chicago for the U.S. Department of Energy Nanofabrication H. Hau Wang Argonne National Laboratory Materials Science Division Symposium on Digital Fabrication Aug 12, 2005

2 Why going Nano?1 nm = m Chemistry – higher reactivity High surface area – Good for chemical and biochemical sensors Higher sensitivity and faster response time Good for heterogeneous catalysis The larger the surface area, the higher the reactivity. High level of reaction control Material – better mechanical strength UNCD Ultra-nano-crystalline diamond (ANL/CNM) Ultra-thin and tough coating - prolong equipment life time Carbon-nanotubes – Ultra-high mechanical strength Physics – quantum confined phenomena and designed physical properties Quantum dots, Near field optics, plasmonics High density magnetic storage – nanoclusters Ideal spring nanomagnet - High magnetization and coercivity

3 Nanofabrication – current status Top-down Fabrication techniques e-beam lithography FIB – focused ion beam DPN – dip pen nanolithography Requires major facilities, control below 100 nm is a challenge, can not obtain high aspect ratio. Bottom-up Synthesis – The nano-scaled objects are limited to simple geometrical shape: sphere, cube, triangle, thin film, wire, tube, etc. – No standard 3D morphological control – Handling and Alignment are difficult Lithographically assisted self-assembly – Combining top-down and bottom-up 1 x 1  m 2 AFM image of self-assembled PEG- PMMA thin film showing partially ordered structure 5 x 5  m 2 AFM image of as-prepared AAO membrane showing domain boundary

4 Nanotubes AAO/Al 2 O 3 /V 2 O 5 nanostructure has been prepared for heterogeneous catalysis studies. Pd nanotubes showed very good hydrogen sensing capability. Cross-Section of Coated AAO After ALD Before ALD 200 nm Bi NT

5 Nanoparticles Au, Co, Co/Pt Nanoparticles – Magnetic storage (X. M. Lin et al.)

6 To understand the dynamics of highly ordered nanocrystal monolayer through evaporation of a nanocrystal colloidal droplet. (J. Phys. Chem. B 2001, 105, 3353) Grazing Incidence Small Angle X-ray Scattering (GISAXS)  Kinetic effects can play an important role in nanocrystal self-assembly.  Fast initial evaporation rate can induce nanocrystals accumulate at the liquid-air interface and undergo a 3D to 2D structural transition to form highly ordered nanocrystal monolayer. Dynamics of Monolayer Nanocrystal Self-assembling Process in Liquid Film Xiao-Min Lin Xiao-Min Lin Suresh Narayanan, Jin Wang MSD/CHM Advanced Photon Source

7 Nanowires Various metallic (Au, Ag, Cu, etc.), superconductive (Pb), ferromagnetic (Co, Ni, etc.) nanowires have been made with anodized aluminum oxide (AAO) templates. Multi-segmented (Co/Cu), (Au/Ni – Mirkin, Science 2005) nanowires have been prepared with pulsed electro-deposition. Multi-segmented SiNi/Si/SiNi nanowires have been fabricated into integrated nanowire circuits. (Lieber, Nature 2005) Materials Science Division, MSD Center for Nanoscale Materials, CNM 50 nm Au Co 20 nm/Cu 20 nm FM2 (Co) NM (Cu) FM1 (Co) R M H Parallel H AP Parallel  R/R