title: Engineering on-chip nanoporous gold material libraries via precision photothermal treatment.
abstract: Libraries of nanostructured materials on a single chip are a promising platform for high throughput and combinatorial studies of structure-property relationships in the fields of physics and biology. Nanoporous gold (np-Au), produced by an alloy corrosion process, is a nanostructured material specifically suited for such studies because of its self-similar thermally induced coarsening behavior. However, traditional heat application techniques for the modification of np-Au are bulk processes that cannot be used to generate a library of different pore sizes on a single chip. Here, laser micro-processing offers an attractive solution to this problem by providing a means to apply energy with high spatial and temporal resolution. In the present study we use finite element multiphysics simulations to predict the effects of laser mode (continuous-wave vs. pulsed) and thermal conductivity of the supporting substrate on the local np-Au film temperatures during photothermal annealing. Based on these results we discuss the mechanisms by which the np-Au network is coarsened. Thermal transport simulations predict that continuous-wave mode laser irradiation of np-Au thin films on a silicon substrate supports the widest range of morphologies that can be created through photothermal annealing of np-Au. Using the guidance provided by simulations, we successfully fabricate an on-chip material library consisting of 81 np-Au samples of 9 different morphologies for use in the parallel study of structure-property relationships.
authors.affiliation: Department of Biomedical Engineering, University of California - Davis, Davis, CA 95616, USA.
authors.forename: Christopher A R
authors.initials: CA
authors.lastname: Chapman
authors.affiliation: Department of Electrical and Computer Engineering, University of California - Davis, Davis, CA 95616, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, CA 94551, USA. ibo@llnl.gov.
authors.forename: Juergen
authors.initials: J
authors.lastname: Biener
authors.affiliation: Department of Electrical and Computer Engineering, University of California - Davis, Davis, CA 95616, USA.
authors.forename: Erkin
authors.initials: E
authors.lastname: Seker
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, CA 94551, USA. ibo@llnl.gov.
authors.forename: Monika M
authors.initials: MM
authors.lastname: Biener
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, CA 94551, USA. ibo@llnl.gov.
authors.forename: Manyalibo J
authors.initials: MJ
authors.lastname: Matthews
mesh_terms: D000497:Alloys; D015374:Biosensing Techniques; D003198:Computer Simulation; D004058:Diffusion; D020342:Finite Element Analysis; D005898:Glass; D006046:Gold / Q000737:chemistry*; D006358:Hot Temperature; D007834:Lasers; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning / Q000379:methods; D049329:Nanostructures / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D010777:Photochemistry / Q000379:methods; D016062:Porosity; D012825:Silicon / Q000737:chemistry; D012834:Silver / Q000737:chemistry*
chemical_list: D000497:Alloys; D012834:Silver; D006046:Gold; D009584:Nitrogen; D012825:Silicon