Three-dimensional fabrication of metallic micro/nanostructures by two-photon polymerization for metamaterials

We report on selective metal deposition over complex polymer structures formed by two-photon induced photopolymerization (TPP) technique. Periodic three-dimensional (3D) polymer micro/nanostructures are fabricated by means of a microlens array to produce multiple spots from a single-beam femtosecond laser amplified by a regenerative amplifier. The photopolymerizable resin and the glass substrate are chemically modified, and a pre-treatment with SnCl2 is applied before realizing a uniform silver coating by electroless plating. This preparation enables a selective deposition of small silver particles only on the polymer surface all over the sample and to avoid metal deposition on the substrate. Electrical measurements show the structures to be highly conductive with typical resistivities ρ approx. 10-7 Ωm, only a few times larger than the value for bulk silver. By taking advantage of the high accuracy and arbitrary shape modeling of TPP fabrication, we can realize complex periodic and/or metallic micro-nanostructures which were so far out of reach. Thus, a straightforward application could be the realization of metamaterials. The processing efficiency of our technique is demonstrated with the fabrication of several large samples, created by more than 700 objects written in parallel and metallized with silver.

[1]  S. Kawata,et al.  Three-dimensional microfabrication with two-photon-absorbed photopolymerization. , 1997, Optics letters.

[2]  Seth R. Marder,et al.  Two-photon polymerization initiators for three-dimensional optical data storage and microfabrication , 1999, Nature.

[3]  Satoshi Kawata,et al.  Finer features for functional microdevices , 2001, Nature.

[4]  Yoshio Kobayashi,et al.  Deposition of Silver Nanoparticles on Silica Spheres by Pretreatment Steps in Electroless Plating , 2001 .

[5]  Hongjie Dai,et al.  A New Scanning Probe Lithography Scheme with a Novel Metal Resist , 2002 .

[6]  Seth R. Marder,et al.  Laser and Electron‐Beam Induced Growth of Nanoparticles for 2D and 3D Metal Patterning , 2002 .

[7]  Saul Griffith,et al.  Nanostructure fabrication by direct electron-beam writing of nanoparticles , 2002 .

[8]  Tianyue Yu,et al.  An efficient two-photon-generated photoacid applied to positive-tone 3D microfabrication. , 2002, Science.

[9]  David N. Batchelder,et al.  Simple Chemical Method for Forming Silver Surfaces with Controlled Grain Sizes for Surface Plasmon Experiments , 2003 .

[10]  Heh-Nan Lin,et al.  Fabrication of metallic nanostructures by atomic force microscopy nanomachining and lift-off process , 2004 .

[11]  David R. Smith,et al.  Metamaterials and Negative Refractive Index , 2004, Science.

[12]  Tommaso Baldacchini,et al.  Multiphoton laser direct writing of two-dimensional silver structures. , 2005, Optics express.

[13]  Satoshi Kawata,et al.  Metal Deposition Deep into Microstructure by Electroless Plating , 2005 .

[14]  Hong‐Bo Sun,et al.  Multiple-spot parallel processing for laser micronanofabrication , 2005 .

[15]  S. Kawata,et al.  Two-photon-induced reduction of metal ions for fabricating three-dimensional electrically conductive metallic microstructure , 2006 .

[16]  Satoshi Kawata,et al.  Selective electroless plating to fabricate complex three-dimensional metallic micro/nanostructures , 2006 .

[17]  Linjie Li,et al.  Selective functionalization of 3-D polymer microstructures. , 2006, Journal of the American Chemical Society.

[18]  Satoshi Kawata,et al.  Three-dimensional fabrication of metallic nanostructures over large areas by two-photon polymerization. , 2006, Optics express.