My previous works (updated on February 15, 2023)

(1) October 1986 - March 1987,

Prof. Yoshiya HARADA's laboratory at the Department of Chemistry, College of Arts and Sciences, Univ. Tokyo, BA student

Study of cycrosilane by ab initio MO calculation, He I Ultraviolet Photoelectron Spectroscopy, and Penning Ionization Electron Spectroscopy

I calculated the energy states of cyclosilanes (n=3,4,5,6) by ab initio molecular orbital (MO) method, and we measured He I Ultraviolet Photoelectron Spectra, and Penning Ionization Electron Spectra of them. I found that the orbital energy for the highest occupied molecular orbital (HOMO) is minimum and the energy gap between HOMO and lowest unoccupied molecular orbital (LUMO) is the largest at n=5.

(2) April 1987 - March 1992,

Prof. Koichi OHNO's laboratory at the Department of Chemistry, College of Arts and Sciences, Univ. Tokyo (Prof. Ohno has moved to Department of Chemistry, Tohoku Univ.), Master and Doctor course student

Study of Penning ionization process by velocity- and angular- resolved Penning ionization electron spectroscopy

We developed metastable helium atom (He*(23S)) beam source at the beam intensity of 1.6x1015 s-1 sr-1. We also developed "Velocity-resolved Penning ionization electron spectroscopy" by combining the method of Penning ionization electron spectroscopy with time-of-flight (TOF) method.[1] The both developments enables us the experiment of the velocity (collision-energy) dependence of the final electronic state resolved Penning ionization partial cross section. We got the information of the anisotropy of the interaction potential between gaseous molecule and He*(23S)). For example, in case of nitrogen molecule, the repulsive interaction potential is steep when He* approaches toward the direction of nitrogen molecular axis, whereas gentle when He* approaches toward the perpendicular direction of nitrogen molecular axis. I got Doctor degree with this study.

(3) April 1992 - April 1994,

Special Researcher, Basic Science Program, (Post Doctor, c/o Dr. Masakazu Aono), Surface and Interface Laboratory, The Institute of Physical and Chemical Research (RIKEN)

(a) Study of the initial stage of the Au deposition on Si(111) clean surface by scanning tunneling microscopy

  We have studied the surface structure when Au atoms are deposited at 0.2-1.5 monolayer on Si(111) clean surface by scanning tunneling microscopy (STM). Si(111) alpha-root3xroot3-R30degree-Au surface structure appears at 0.7-1.0 monolayer. The root3xroot3 structure consists of domain A which has root3xroot3-ordered structure and domain B which has a distorted structure. Depositing Au atoms, continual phase transition has been observed by increasing the area ratio of the domain B. From the analysis of the neighbor distance between the protrusions on the STM images, it is concluded that the domain B has a similar structure with Si(111)6x6-Au. We also observed several phases in the 6x6 structure. [2]

(b) The thinnest cloth in the world, "atomic cloth" observed by STM
(From April to September 1993, I hold an additional post of a part-time instructor at Dept. Mater. Sys. Eng., Tokyo Univ. Agri. Tech.)

We succeeded to observe the macromolecule "atomic cloth", comprised of alkylchains and crosslinked polydiacetylenes and polyacetylenes, whose thickness is 0.04 nm (neglecting hydrogen atoms), it is carbon monoatomic layer.
(This work was done with Dr. Hiroyuki Ozaki in Tokyo University of Agriculture and Technology who prepared the "atomic cloth". [3])

(4) April 1994 - September 1994

Postdoctoral position (c/o Dr. Christoph Gerber), IBM Research Division, Zurich Research Laboratory

(a) Study of self-assembled monolayer of alkanethiolates on Au surface by high-gap impedance (tera-ohm) STM

We have studied self-assembled monolayers (SAM) of alkanethiolates and dialkyl disulfides with different tail functional groups adsorbed on Au surface by the special STM of which we can observe the image at 1 pA. I changed the tunneling signal into SOUND, which is a convenient way to monitor the tunneling current. We succeeded to observe an SAM image of alkanethiolates with azobenzene-functional group [4], and molecular-resolved images of two different tail functional groups; -OH and CH3, and azobenzene-group and CH3. [5]

(b) Observation of octa t-butyl tetraphenylporphirin on Cu surfaces by STM

We have studied the high-resolved images of octa t-butyl tetraphenylporphirin on Cu surfaces by STM.[6]
(This work was done with Dr. J. K. Gimzewski et al. (Dr. Gimzewski has moved to UCLA.), and Dr. Ken-ichi Sugiura who synthesized the porphyrin (Dr. Sugiura has moved to Tokyo Metropolitan University.).)

(5) November 1994 - March 1997

Assistant Researcher (Prof. Shozo Ino's Laboratory), Department of Physics, Graduate School of Science, University of Tokyo

(a) Development of metastable oxygen beam

  By the mixed plasma discharge of oxygen gas and rare-gas, we produced metastable oxygen beam. The beam will enable us to prepare oxide thin films low pressure since the most of the introduced oxygen will react with the irradiated surface.[7] The beam source can change to metastable nitrogen beam source by changing the oxygen gas into nitrogen gas.

(b) Multiply-Twinned Particle (MTP) micelle

We created micelle-like aggregates comprised of Au MTP, which had discovered by Prof. Ino in 1966, at the average diameter of 7 nm and self-assembled propionicacidthiolates. We named the aggregates "MTP-micelle". We developed a simple method to prepare the MTP micelles. [8] We checked the size of the core Au MTPs by transmission electron microscopy (TEM). From the proton NMR spectrum of MTP-micelle, compared with those of mercaptopropionic acid and the disulfide, we concluded that the mercaptopropionic acid thiolates form dimers (disulfides) and chemisorbed on the Au MTPs. We demonstrated an application of the Au MTP-micelle; Au deposition on Si(111) surface without using vacuum evaporation. A droplet of the MTP-micelle aqueous solution on Si(111) wafer at air, and introduced in vacuum chamber. Flushing the Si(111) wafer at 1173 K for ca. 0.5 s, 6x6 RHEED pattern was observed, which means that Au monolayer was formed on the Si(111) surface. [9] We confirmed this technique by photoelectron spectroscopy (UPS, XPS), and metastable impact electron spectroscopy, worked with Prof. V. Kempter at Technische Universitat Clausthal [10]

(6) April 1997 - March 2001

Assistant Researcher and Associate Professor (Prof. Kusunoki's Laboratory), Research Institute for Scientific measurement (RISM), Tohoku University

(a) RHEED and STM/AFM study of diamond and related materials
worked with Dr. Toshihiro Ando in NIRIM (supported by CREST, JST)

For the studies of the surfaces of diamond and related materials, we have constructed an apparatus of consisted of 3 vacuum chambers of (1) UHV chamber containing RHEED, (2) UHV chamber containing STM and AFM (Atomic Force Microscope), and (3) molecular beam chamber. Main results were as follows;
1. By irradiating an ethylene molecular beam on Si(100) surface at the surface temperature of 700 C, with the nozzle of the beam heated at 800 C, silicon carbide (SiC) was epitaxially grown. Especially, at the center of the beam irradiation, not only SiC but graphite-like carbon was grown. This data shows that surface reaction is governed by flux. [11]

2. The (111) surface of the single crystal of cubic boron nitride produced by the epitaxial growth on a diamond surface was observed by AFM at atomic-scale resolution. Two kinds of domains were observed at the friction mode, which is attributed to the chemical property of the outermost surface. [12]

3. Homoepitaxial diamond surfaces grown by microwave plasma-assisted chemical vapor deposition (CVD) were studied by RHEED, STM and AFM. Although we succeeded to obtain AFM images with an atomic-scale resolution [13], no steps and defects was observed while STM images showed them. [14]
(b) Development of Total-reflection angle soft-Xray spectroscopy combined with reflection high-energy electron diffraction (RHEED-TRASXS)worked with Prof. Shozo Ino in Utsunomiya University

Combining total reflection angle soft X-ray spectroscopy with reflection high-energy electron diffraction, we developed a novel method to observe structural and stoichiometric properties of a surface simultaneously. This method will be powerful when the problem of the white noise caused by Bremsstrahlung is solved. [15]

(c) Production of MTP-micelle:

I collaborated with Dr. D. Fujita at Extreme High Vacuum Research Station, NRIM in order to produce plenty of MTP-micelles. (Visiting Researcher from August 1998 to March 1999). This work was supported by Advanced Institute of Technology (1998). Also, from the support of Tanaka Kikinzoku Co. Ltd., we produced gold icosahedron and soccer-ball from nano-scale [16] to centimeter-scale [17].

(7) April 2001 - September 2006

Senior Researcher, Visionarts, Inc.; Visionarts Research, Inc.

(a) Basic research on nanotechnology

I invented a method to produce transmission X-ray lens [18], nanofibers [19], and halation protection filter for reflection high-energy electron diffraction (RHEED) [20]. We established our laboratory in Manhattan, but closed due to September 11.

(b) Molecular phase memory (Visiting Scientist at The Pennsylvania State University and Visiting Professor at Tokyo Metropolitan University)

I invented a method to record phase information to a single molecule, with Prof. Ken-ichi Sugiura of Tokyo Metropolitan University.[21] In order to realize the invention, I visited Prof. Paul S. Weiss Group of The Pennsylvania State University and studied experimentally by scanning tunneling microscopy. I found that double-decker phthalocyanine/porphirin molecules could be applied for the molecular phase memory when I visited Dr. Dennis P. Arnold Group of Queensland University of Technology, Australia. I collaboreted with Prof. Jianzhuang Jiang of Shandong University, China who synthesized the molecules, and we suceeded to align and control the double-decker molecules on graphite surface.[22]

(8) September 2006 - September 2007

CREST Researcher, JST, c/o Prof. Tomoji Kawai, ISIR-SANKEN, Osaka University

DNA ligandation with octylamine and high resolution imaging

We developed a method to stretch and stabilize DNA oligomers on graphite surface by liganding the phosphoric acids of DNA with octylamines. High-resolution imaging was achieved by scanning tunneling microscopy at the tunneling current less than 1 pA. [23].

(9) October 2007 - March 2008

Researcher, Prof. Yuji Takakuwa Group, IMRAM, Tohoku University, supported by CREST, JST

Development of graphene synthesis by plasma CVD

We developed a method to produce graphene on silicon wafer and mica with a plasma chemical vapor deposition (CVD), without using catalysts.[24]

(10) March 2008 - February 2010

Assistant Research Professor, Prof. K.W. Hipps Group, Department of Chemistry, Washington State University

High-resolution imaging of phthalocyanines with scanning tunneling microscope

We observed phthalocyanines and their derivatives by scanning tunneling spectroscopy with high-resolution to see internal structures of the molecules. We determined the surface structures of iron phthalocyanines on silver (111) surface, not only the periodic structures but also the orientation of the phthalocyanine relative to the surface.[25] Also, we demonstrated to control surface periodic structure by changing the polalized solvent that is used during the adsorption process.[26]

(11) March 2010 - March 2014

Research Professor, Department of Physics and WCU Program, Konkuk University

Development of ion-selective nanopipette probe for cell observation

We have developed a nanopipette probe available to separate sodium and potassium ions in aqueous solution with a poly(vinyl chloride) filter containing crown ethers as a filter.[27] We also developed a new tool of Besocke-type Beetle robot with a nanopipette probe for cell surgey experomemt.[28] Moreover, in collaboration with Professor Futoshi Iwata at department of mechanical enginnering, Shizuoka University, we succeeded in observing the difference of the local concentration in and out of HeLa cells with our ion-selective nanopipette probes.[29] We discovered an interesting phenomenon; non-linear oscillation of ionic current in nanopipette [30] and investigate the rectification of ionic current in nanopipette. We summerized our work in a review paper.[31]

(12) April 2014 - March 2015

Project Professor, RcMcD, Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University

Development of automatic cell injection system

There are many apparatus on microinjection to living cells. However, these injections are manual; high skill and experiences are required for the cell injection without any damage to the cells. Moreover, hundred times more cell injection is required to obtain the data worth while analizing in statistics but doing it by manual is next to impossible. Several companies have already tried to make automatic cell injection system, but the system only kills most of the cells by the injection and few cells survived by the auto-injection. Here, using my previous experiences on the ab initio construction of scanning tunneling microscopes including the controller, I am going to develop an automatic injection system with some feedback loops for the safe injection to let the cells survive after the injection.[32]

[1] T. Takami and K.Ohno, J. Chem. Phys. 96 (1992) 6523.
[2] T. Takami et al., Jpn. J. Appl. Phys. 33 (1994) 3688.
[3] T. Takami et al., Angew. Chem. (German) 24 (1997) 2909; Angew. Chem. Int. Ed. Engl. 24 (1997) 2755.
[4] H. Wolf et al., J. Phys. Chem. 99 (1995) 7102.
[5] T. Takami et al., Langmuir 11 (1995) 3876.
[6] see Science 271 (1996) 181.
[7] T. Takami and S. Ino, Patent (Japan), Publication No. 08316540.
[8] T. Takami and S. Ino, Patent (Japan), Publication No. 09278598.
[9] T. Takami and S. Ino, Jpn. J. Appl. Phys. 36 (1997) L815.
[10] T. Takami et al., Surf. Sci. 407 (1998) 140.
[11] T. Takami et al., Appl. Surf. Sci. 169-170 (2001) 300.
[12] T. Takami et al., Appl. Phys. Lett. 73 (1998) 2733.
[13] T. Takami et al., Surf. Sci. 440 (1999) 103.
[14] T. Takami et al., J. Vac. Sci. Technol. B 18 (2000) 1198.
[15] Report of the Grand-in-aid of Scientific Research from The Ministry of Education, Science, Sports, and Culture in Japan (Japanese), No.11559002 (2001).
[16] T. Takami et al., Appl. Surf. Sci., 130-132 (1998) 834.
[17] T. Takami and T. Aizawa, Patent (Japan), Publication No.2000-066579.
[18] US Patent 6,385,291.
[19] US Patent Application No. 09/871,029.
[20] US Patent 6,873,403; 6,878,509.
[21] US Patent 6,762,397.
[22] T. Takami et al., J. Chem. Phys. C 111 (2007) 2077.
[23] T. Takami et al., Surf. Sci. Lett. 602 (2009) 3201.
[24] T. Takami et al., e-Journal Surf. Sci. Nanotech. 7 (2009) 882.
[25] T. Takami et al., Surf. Sci. 603 (2009) 3201.
[26] T. Takami et al., J. Phys. Chem. C 113 (2009) 17479.
[27] T. Takami et al., Jpn. J. Appl. Phys. 50 (2011) 08LB13.
[28] T. Takami et al., Jpn. J. Appl. Phys. 51 (2012) 08KB12.
[29] T. Takami et al., T. Takami et al., J. Appl. Phys. 111, 044702 (2012).
[30] X. L. Deng et al., J. Phys. Chem. C 116 (2009) 14857.
[31] T. Takami et al., Nano Convergence 1 (2014) 17. [32] T. Takami et al., e-J. Surf. Sci. Nanotech. 13 (2015) 79.