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Papers by Masanobu Iwanaga

Meeting abstracts of the Physical Society of Japan, Aug 25, 2008

Nano Letters, Jun 14, 2023

Meeting abstracts of the Physical Society of Japan, Feb 28, 2007

The Japan Society of Applied Physics, Jan 26, 2021

The Japan Society of Applied Physics, Jan 28, 2020

Advanced Healthcare Materials, Apr 23, 2022

Shape-memory polymers are promising materials in numerous emerging biomedical applications owing ... more Shape-memory polymers are promising materials in numerous emerging biomedical applications owing to their unique shape-memory characteristics. However, simultaneous realization of high strength, toughness, stretchability while maintaining high shape fixity (Rf ) and shape recovery ratio (Rr ) remain to be a challenge that hindered their practical application. Herein, we report a novel shape-memory polymeric string (SMP string) that is ultra-stretchable (up to 1570%), strong (up to 345 MPa), tough (up to 237.9 MJ m-3 ) and highly recoverable (Rf averagely above 99.5%, Rr averagely above 99.1%) through a facile approach fabricated solely by tetra-branched poly(ε-caprolactone). Notably, the shape-memory contraction force (up to 7.97 N) of this SMP string is customizable with the manipulation of their energy storage capacity by adjusting the string thickness and stretchability. In addition, this SMP string displays a controllable shape-memory response time and demonstrates excellent shape-memory-induced contraction effect against both rigid silicone tubes and porcine carotids. This novel SMP string is envisioned to be applied in the contraction of blood vessels and resolve the difficulties in the restriction of blood flow in minimally invasive surgeries such as fetoscopic surgery of sacrococcygeal teratoma (SCT). This article is protected by copyright. All rights reserved.

Optics Express, Mar 31, 2010

We report on the second harmonic generation (SHG) in 2D periodically polarity-inverted (PPI) ZnO ... more We report on the second harmonic generation (SHG) in 2D periodically polarity-inverted (PPI) ZnO heterostructures. The grating structures with nanometer-scale periodicity are fabricated on (0001) Al(2)O(3) substrates by using the in situ polarity inversion method. The achievements of SHG with grating in fabricated PPI ZnO structures are demonstrated under consideration of quasi phase matching conditions. In general, grating formation using the this periodical array of differnet polar surface can be extended to the other heteroepitaxial systems with polarity characteristics.

Biosensors

One of the most significant characteristics, which biosensors are supposed to satisfy, is robustn... more One of the most significant characteristics, which biosensors are supposed to satisfy, is robustness against abundant molecules coexisting with target biomolecules. In clinical diagnoses and biosensing, blood, plasma, and serum are used daily as samples. In this study, we conducted a series of experiments to examine the robustness of all-dielectric metasurface biosensors, which comprise pairs of a highly fluorescence-enhancing silicon nanopellet array and a transparent microfluidic chip. The metasurface biosensors were shown to have high performance in detecting various targets from nucleic acids to proteins, such as antigens and antibodies. The present results show almost four-order wide dynamic ranges from 0.16 ng/mL to 1 μg/mL for prostate-specific antigen (PSA) and from 2 pg/mL to 25 ng/mL for carcinoembryonic antigen (CEA). The ranges include clinical criteria for PSA, 4 ng/mL and CEA, 5 ng/mL. To date, a systematic demonstration of robustness has not been reported regarding th...

Kyoto University (京都大学)0048新制・課程博士博士(人間・環境学)甲第10306号人博第193号14||157(吉田南総合図書館)新制||人||48(附属図書館)UT51-... more Kyoto University (京都大学)0048新制・課程博士博士(人間・環境学)甲第10306号人博第193号14||157(吉田南総合図書館)新制||人||48(附属図書館)UT51-2003-H727京都大学大学院人間・環境学研究科環境相関研究専攻(主査)教授林哲介, 教授宮本嘉久, 教授後藤喬雄学位規則第4条第1項該

The Japan Society of Applied Physics, Jul 9, 2020

2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), 2019

A new class of planar, wavelength-thick optical components exhibiting exceptional optical propert... more A new class of planar, wavelength-thick optical components exhibiting exceptional optical properties have emerged in recent years[1–3]. These artificial interfaces, known as metasurfaces, rely on the scattering properties of the subwavelength structures patterned at a boundary to mold the wavefront of light in almost any desired manner. Beside numerous experimental demonstrations, only a handful of low cost and fabrication friendly materials are suitable for their practical implementations. To further develop this technology towards dynamic tuning, broadband application and industrial production, new materials and new fabrication methods are required.

Biosensors and Bioelectronics, 2021

We demonstrate highly sensitive fluorescence (FL) biosensors made of plasmon-photon-hybrid high-e... more We demonstrate highly sensitive fluorescence (FL) biosensors made of plasmon-photon-hybrid high-emittance metasurfaces, which are hybrid structures composed of perforated silicon waveguides and stacked complementary (SC) gold nanostructures. The SC metasurfaces are applicable to a wide range of targets from antibodies to nucleic acids. As a test bed, a representative antibody of immunoglobulin G is immobilized on the metasurfaces through microfluidic paths and then is directly detected in a scaled manner even at a very low concentration of 5 pg mL-1, i.e., 34 fM. Moreover, a cancer marker of p53 antibody is indirectly detected on the SC metasurfaces at a low concentration of 50 pg mL-1, which is significantly lower than the medical diagnosis criterion of a few ng mL-1. Furthermore, single-strand DNAs that are oligonucleotides and complementary to SARS-CoV-2 RNA are detected with 1 h immobilization time in the range of fmol mL-1 in a scaled manner. These experimental results indicate that the present FL metasurface sensors function efficiently as biosensors for a wide range of biomarkers.

Plasmonic Resonators, 2016

Photoacoustic (PA) signals of CsPbCl3 crystals have been examined in a wide temperature range of ... more Photoacoustic (PA) signals of CsPbCl3 crystals have been examined in a wide temperature range of 150–300 K. The PA signals, induced by ns-pulsed laser excitation of electronic states and detected with a piezoelectric transducer, are thermoelastic ultrasonic waves lasting for hundreds of microseconds. The wavelet analysis of the PA wave has clarified that the thermoelastic wave includes several MHz components. The PA signals have been also made use of in order to examine phase transitions at low temperatures in the crystal. Changes of PA signals strongly suggest that second-order phase transitions take place at low temperatures around 200 K.

The Japan Society of Applied Physics, 2015

The Review of Laser Engineering, 2016

A new class of optical metamaterials is attracting great attention: metasurfaces, which are ultra... more A new class of optical metamaterials is attracting great attention: metasurfaces, which are ultrathin twothe influence of absorption loss in metals more than three-dimensional optical metamaterials. In particular, the recent development of nanoimprint lithography technologies is increasing the possibility of practical applications of metasurfaces. Metasurfaces manipulate light waves with a huge degree of freedom, and also enhance various optical processes through the high local density of the states of