讲座题目：Femtosecond Laser3D Processing for Fabrication of Functional Micro- and Nanosystems
主讲人： Koji Sugioka
Koji Sugioka received his B. S., Ms. Eng., and Dr. Eng. Degrees inelectronics from Waseda University (Japan) in 1984, 1986, 1993, respectively.He Joined RIKEN in 1986 and is currently a Team Leader of Advanced LaserProcessing Research Team at RIKEN Center for Advanced Photonics. He isconcurrently a guest professor at Osaka University and Tokyo Denki University.His current research interests include ultrafast laser processing formicroelectronic, optoelectronic and biological applications. He is currently amember of the board of directors of the Laser Institute of America (LIA), Int.Academy of Photonics and Laser Engineering (IAPLE), Japa Laser ProcessingSociety (JLPS) and the Japan Society of Laser Technology (JSLT), and a Fellowof SPIE, OSA, LIA and IAPLE. He is also an editor-in-chief of Journal of theLaser Micro/Nanoengineering (JLMN), and an editor of Opto-Electronic Advances(OEA), Advanced Optical Technology (AOT), and Intl. Journal of ExtremeManufacturing (IJEM).
The extremely high peak intensity associated with ultrashort pulse width offemtosecond (fs) laser allows us to induce nonlinear multiphoton absorptionwith materials that are transparent to the laser wavelength. More importantly,focusing the fs laser beam inside the transparent materials confines thenonlinear interaction only within the focal volume, enabling three-dimensional(3D) micro- and nanofabrication. This 3D capability offers three differentschemes, which involve undeformative, subtractive, and additive processing. Theundeformative processing preforms internal refractive index modification toconstruct 3D optical microcomponents including optical waveguides insidetransparent materials. Subtractive processing can realize the directfabrication of 3D microfluidics, micromechanics, and photonic microcomponentsin glass. Additive processing represented by two-photon polymerization (TPP)enables the fabrication of 3D micro- and nanostructures made of not onlypolymer but also protein for photonic, microfluidic, and biologicalapplications. Furthermore hybrid approach of different schemes can create muchmore complex 3D structures and thereby promises to enhance functionality ofmicro- and nano-devices.
For example, a successiveprocedure of subtractive 3D glass micromachining and the undeformative opticalwaveguide writing realizes optofluidics for detection, manipulation, andsorting of bio samples . Meanwhile, combination of subtractive 3D glassmicromachining and additive TPP is not only an instrument that can tailor 3Dstructures but also a tool to fabricate biomimetic in vivo environment inside glassmicrofluidic chips . Specifically, the subtractive 3D glass micromachiningcan flexibly fabricate 3D microfluidic structures embedded in glass microchipswithout a complicated procedure of stacking and bonding of glass substrates.Successive TPP can then integrate complex shapes of polymer structures with asub-micrometer feature size due to its high fabrication resolution to createbiomimetic structures inside the glass microfluidics. Thus, such advancedbiochips can be utilized to study the mechanism of cancer cell invasion andmetastasis . Furthermore, the subtractive 3D glass micromachining followedby femtosecond laser direct write ablation and successive electroless metalplating enables selective metalization of 3D glass microfluidic chips forelectrical control of living cell movement in 3D . This selective metallizationtechnique is also applied to fabricate 3D microfludic surface-enhanced Ramanspectroscopy (SERS) sensers with an extremely high enhancement factor byformation of periodic nanodot structures on the plated metal thin fills .
This talk presents our recentachievements on fabrication of functional 3D micro- and nano-systems includingmicrofluidics, optofluidics, microsensors, and 3D proteinaceous microstructuresby femtosecond laser 3D processing.
 K. Sugioka, Y. Hanada, and K. Midorikawa, “Three-dimensionalfemtosecond laser micromachining of photosensitive glass forbiomicrochips, Laser Photon. Rev. 3, 386-400 (2010).
 D. Wu, J. Xu, L. Niu, S. Wu, K. Midorikawa, and K. Sugioka, “In-channelintegration of designable microoptical devices using flat scaffold-supportedfemtosecond-laser microfabrication for coupling-free optofluidic cellcounting”, Light Sci. Appl. 4, e228 (2015).
 F. Sima, H. Kawano, A. Miyawaki, L. Kelemen, P. Ormos, D. Wu, J. Xu, K.Midorikawa, and K. Sugioka, “3D biomimetic chips for cancer cell migration innanometer-sized spaces using “ship-in-a-bottle” femtosecond laser processing”,ACS Appl. Bio Mater. 1, 1667-1676 (2018).
 J. Xu, H. Kawano, W. Liu, Y. Hanada, P. Lu, A. Miyawaki, K. Midorikawa,and K. Sugioka, “Controllable alignment of elongated microorganisms in a 3Dmicrospace using electrofluidic devices manufactured by hybrid femtosecondlaser microfabrication”, Microsystems Nanoengin. 3, 16078 (2017).
 S. Bai, D. Serien, A. Hu, and K. Sugioka, “3D microfluidic SERS chipsfabricated by all-femtosecond-laser-processing for real-time sensing of toxicsubstances”, Adv. Func. Mater. 28, 1706262 (2018).