Past experience & achievements of the person the university proposes to appoint(significant academic contribution(s), details of academic awards received, key
academic research findings, and their curriculum vitae.)Dr. Hiroshi Masuhara is one of the most reputable Japanese chemists, awarded The
Purple Medal (紫綬褒章) and The Order of Sacred Treasure, Gold Ray with Double
Neckless (瑞宝中綬章), honored internationally The Porter Medal (corresponding toNobel Prize in photochemistry), and Academicians of The Royal Academy of Belgiumand National Academy of Sciences India. This is due to his pioneering study on
nano/micro molecular systems exploring their new photochemical and photophysicalphenomena by developing time-resolved spectroscopy, imaging, and manipulation
methods and by elucidating their dynamics and mechanism. He has opened newinterdisciplinary area of molecular photo-science, whose results are published as ~560
papers, ~120 reviews, and ~20 books. His pioneering works have attracted many young
researchers and graduate students. Now 63 doctors graduated/educated from Masuhara
Laboratory/Project and 40 researchers coached in Masuhara Project are working in therelevant areas of molecular photo-science as professors and distinguished researchers in
8 countries including Taiwan.
This long developing academic research by Dr. Masuhara before shifting to NCTU in2008 is summarized as “Laser Nano Chemistry: Methodology and Molecular Nano
Dynamics”. This consist of 3 parts.

1) Laser Nano Spectroscopy and Nano Photochemistry
Photophysical and photochemical dynamics of nano-crystals, nm-thin films and nmsurface/interface layers of solids were measured and analyzed with high energy andtemporal resolutions similar to those in solution. Ultrafast intersystem crossing, charge
separation, exciplex formation, and photothermal heating processes characteristic of the“solid” state were elucidated and first reported by the Masuhara group for aromatic
molecules, dyes, EDA complexes, TiO2, polymers, and resists. Spectroscopy of single
nanoparticles was examined as functions of their shape, size, morphology, internalstructure, and environment. Novel nm size effects on aromatic/polymer crystals andpolymer nanospheres were investigated and their origins were confirmed to be structuralconfinement, namely, size-dependence of crystal lattice softening, molecular packing,and polymer conformation. These novel effects are characteristic of molecular material,and completely different from well-known nm size effects of semiconductors and metals
which are due to electron confinement.
2) Laser Nano Manipulation and Chemistry of Photon Pressure
A focused near-infrared laser beam exerts mechanical force, called as photon pressure,on nanomaterials, enabling their trapping and manipulation. The optical trapping studies
have been conducted mostly by physicists and optical engineers, while its extension tochemistry was started by the Masuhara group. By examining various polymer andsupramolecular systems, Dr. Masuhara elucidated, for the first time, molecular structurephoton pressure relation which opens a new field that could be coined “chemistry ofphoton pressure”. This is further being extended to trapping dynamics of single
nanoparticles in solution at room temperature. He also developed a method of 3dimensional trapping and manipulation of nanoparticles and applied it to fix thenanoparticles onto a substrate. The nanoparticles were freely patterned with resolution ofa few ten nm in solution. Although the spatial resolution is less than that of the 2dimensional surface manipulation by a STM tip at low temperature under vacuum, muchbroader applicability is very important for semiconductors, metal nanoparticles,
biological material, cells, and protein crystals.
3) Laser Nano Ablation: Dynamics and Bio Application
Intense pulsed laser excitation of nano-sized droplets, aggregates, crystals, powders, andfilms generates high density excited states and intermediates. Their mutual interactions
and their successive absorption of excitation photons lead to ablation, expansion andsubsequent contraction, surface protrusion, and so on. The Masuhara group developed
time-resolved imaging methods to probe laser-induced morphological dynamics andcombined them with the time-resolved spectroscopy. They extended systematic studies
on nanosecond-, picosecond, and femtosecond laser ablation and related phenomena anddetermined rates of expansion, surface roughening, ablation, and contraction. They
demonstrated how electronic excitation of molecules in solids evolves and leads tomorphological changes. Based on these results, molecular mechanisms of laser ablation
was proposed; cyclic multiphotonic absorption mechanism for ns-excitation and atransient pressure mechanism due to very rapid electronic-vibrational energy conversion
for fs-excitation. All the processes are within the framework of a classic Jablonski
diagram without additional states and intermediates such as plasma. Hence laser ablation
and related dynamics are now understood as typical nonlinear photochemical phenomena.
By utilizing the transient pressure induced by fs-excitation, Masuhara and his colleagues
unraveled novel laser ablation phenomena and developed new methodologies.
Femtosecond multiphoton excitation of molecular films gives discrete and multistep
etching, fs ablation of microcrystals in solution gives the smallest nanocrystal of a dyewith the diameter of 13 nm by top-down method, and the shockwave induced by transientpressure can manipulate individual living cells from a substrate without damage. Dr.
Masuhara also succeeded in the preparation of proteins crystals with high quality andtheir model compounds by introducing femtosecond pulse into supersaturated protein
solution. In addition, they succeeded in controlling the crystal growth with femtosecond
multiphoton excitation. These results have important implications in the area ofbioscience.
Prof. Masuhara was invited as a Chair Professor of NCTU in April 2008 and stayed inNCTU since then. Key research results of his Laser Bio/Nano Science Laboratory in DAC
NCTU are classified into the below 3 topics. The research was carried out under the strong
support of ATU (Aiming Top University) Project of MOE and published as ~100 papers
and presented as ~100 invited lectures.

1) Laser Trapping-Induced Molecular Crystallization and Crystal GrowthDr. Masuhara and his group first demonstrated laser trapping-induced crystallizationahead of the world. They have studied systematically sequential behavior of nucleation,growth, and dissolution of amino acids and a protein. Here one representative example ofL-phenylalanine plate-like crystal is described. Its crystal is prepared by a focused
continuous-wave near-infrared laser beam even in unsaturated solution upon the laser
irradiation into the air/solution interface. One single crystal is generated from the focusand continuously grows two-dimensionally while being trapped by the laser. The crystalgrowth is stopped when the laser power is decreased. The crystal size is kept constant fora certain time period, and then the crystal starts dissolution. The growth and dissolution
processes are directly followed under microscope and their rates are determined. Basedon such approach Dr. Masuhara and his members concluded that amino acid crystal isprepared and surrounded by a highly concentrated domain of a few hundreds ofmicrometers consisting of amino acid liquid-like clusters. This crystallization mechanism
receives much attention as a seminal proposal from NCTU and many international
collaborations with Hokkaido and Saitama universities, Tokyo Institute of Technology,
and Nara institute of Science and Technology have been carried out being supported byATU Project.
2) Femtosecond Laser Trapping and Ejection of Dielectric Nanoparticles
We have found a novel trapping and ejection phenomenon of nanoparticle characteristicof femtosecond laser trapping in solution, which has never been reported by CW laser
trapping. The nanoparticles are trapped at the focus and then a rapidly and asymmetricallyalternative nanoparticle ejection is observed as perpendicular to the linear laserpolarization. Since that, a series of nanoparticles trapping experiments, such as
dependences of laser polarization, pulse width and nanoparticle density, have been
investigated in detail to elaborate this phenomenon. We propose that the unique
directional ejection is due to the formation of strongly packed nanoparticle assembly
during fs laser irradiation. In order to confirm the mechanism, we used different
nanoparticles, chemically modified the surface of nanoparticles, introduced a fluorescentprobe dye into the surface, and systematically extended experimental research. Trapping
well generated by femtosecond laser beam that attracts and gathers nanoparticles
repetitively. Inside the trapping well due to an intense femtosecond light field, thehydrophobic surface of nanoparticles enables the formation of an asymmetric assembly.
Scattering and gradient forces are induced and once the scattering force overcomes thetrapping force, the assembly is ejected out to the surrounding. It is worth noting that theassembly was directly observed after being ejected under a certain condition. Theirconclusion that a strongly packed assembly of nanoparticles are fabricated byfemtosecond laser pulse indicates a new potential methodology of light assisted
assembling of molecules and nanoparticles.
3) In-situ Patterning and Controlling of Living Cells by Femtosecond Laser
Femtosecond laser ablation induces bubbling in solution and a formed bubble expands
rapidly form the focus to the outside. This expansion generates supersonic jet loadingmechanical force on living cells and tissues located around the focus. The target cells are
not directly irradiated, so that their photochemical damages are not induced. Furtherfemtosecond laser ablation has superior features due to its photomechanical mechanism,
leading less decomposition at the focus too. This laser ablation bubbling method was
combined with photochemically and photothermally modified surface patterns, and novel
control of living cells was achieved. Femtosecond laser ablation of physiologicalsolutions generates shockwave and cavitation bubbles, and living cells are mechanicallymanipulated in solution and patterned on the modified surface of a glass. Femtosecond
laser ablation fabricating cytophobic and cytophilic domains enable us to form living cellpatterns and to study cell migration and cell–cell interaction. This method will be one ofpossible useful methods to construct future living cell tips and devices. The experimental
studies were carried out under collaboration with Prof. F.-J.Kao of NYMU and Profs. Y.K. Li and F.-Y. Hsu of NCTU, and also Prof. Y. Hosokawa of Nara Institute of Scienceand Technology.