Towards an Accurate Measurement of Thermal Contact Resistance at Chemical Vapor Deposition-Grown Graphene/SiO2 Interface Through Null Point Scanning Thermal Microscopy.

In the development of graphene-based electronic devices, it is crucial to characterize the thermal contact resistance between the graphene and the substrate precisely. In this study, we demonstrate that the thermal contact resistance between CVD-grown graphene and SiO2 substrate can be obtained by measuring the temperature drop occurring at the graphene/SiO2 interface with null point scanning thermal microscopy (NP SThM), which profiles the temperature distribution quantitatively with nanoscale spatial resolution (-50 nm) without the shortcomings of the conventional SThM. The thermal contact resistance between the CVD-grown graphene and SiO2 substrate is measured as (1.

Enabling low-noise null-point scanning thermal microscopy by the optimization of scanning thermal microscope probe through a rigorous theory of quantitative measurement.

The application of conventional scanning thermal microscopy (SThM) is severely limited by three major problems: (i) distortion of the measured signal due to heat transfer through the air, (ii) the unknown and variable value of the tip-sample thermal contact resistance, and (iii) perturbation of the sample temperature due to the heat flux through the tip-sample thermal contact. Recently, we proposed null-point scanning thermal microscopy (NP SThM) as a way of overcoming these problems in principle by tracking the thermal equilibrium between the end of the SThM tip and the sample surface. However, in order to obtain high spatial resolution, which is the primary motivation for SThM, NP SThM requires an extremely sensitive SThM probe that can trace the vanishingly small heat flux through the tip-sample nano-thermal contact.

Quantitative measurement with scanning thermal microscope by preventing the distortion due to the heat transfer through the air.

Because of its high spatial resolution, scanning thermal microscopy (SThM) has been developed quite actively and applied in such diverse areas as microelectronics, optoelectronics, polymers, and carbon nanotubes for more than a decade since the 1990s. However, despite its long history and diverse areas of application, surprisingly, no quantitative profiling method has been established yet. This is mostly due to the nonlocal nature of measurement by conventional SThM: the signal measured by SThM is induced not only from the local heat flux through the tip-sample thermal contact but also (and mostly) from the heat flux through the air gap between the sample and the SThM probe.

In situ curing of sliding SU-8 droplet over a microcontact printed pattern for tunable fabrication of a polydimethylsiloxane nanoslit.

A tunable process for polydimethylsiloxane (PDMS) nanoslit fabrication is developed for nanofluidic applications. A microcontact printing (μCP) of a laterally spreading self-assembled hexadecanethiol (HDT) layer, combined with in situ curing of a sliding SU-8 droplet, enables precise and independent tuning of a nanoslit-mold width and height using a single μCP master mold. The SU-8 nanoslit-mold is replicated using a hard-soft composite PDMS to prevent channel collapse at low (<0.

Quantitative temperature measurement of an electrically heated carbon nanotube using the null-point method.

Previously, we introduced the double scan technique, which enables quantitative temperature profiling with a scanning thermal microscope (SThM) without distortion arising from heat transfer through the air. However, if the tip-sample thermal conductance is disturbed due to the extremely small size of the sample, such as carbon nanotubes, or an abrupt change in the topography, then quantitative measurement becomes difficult even with the double scan technique. Here, we developed the null-point method by which one can quantitatively measure the temperature of a sample without disturbances arising from the tip-sample thermal conductance, based on the principle of the double scan technique.

Nanoscale range finding of subsurface structures by measuring the absolute phase lag of thermal wave.

The need for a subsurface imaging technique to locate and characterize subsurface defects in multidimensional micro- and nanoengineered devices has been growing rapidly. We show that a subsurface heater can be located accurately using the phase lag of a thermal wave. We deduce that the absolute phase lag is composed of four components.

An autopsy case of postpartum acute myocardial infarction associated with postpartum ergot alkaloids administration in old-aged pregnant women.

Cases of acute myocardial infarction (AMI) that occur during pregnancy or postpartum are rarely reported. Ergot derivatives are known to induce the spasmodic contraction of coronary arteries. Administration of ergot derivatives can cause AMI, even in normal healthy people.

Efficacy assessment of CellSlide in liquid-based gynecologic cytology.

Objective: To evaluate the efficacy of CellSlidetrade mark (CS) method in liquid-based gynecologic cytology.

Methods: We compared 1221 specimens prepared by both CS and conventional techniques to evaluate specimen adequacy and cytologic diagnoses. Sensitivity and specificity of these techniques were analyzed in 54 cases using the available histological data.

Correlation between cyclooxygenase-2 and tumor angiogenesis in non-small cell lung cancer.

The role of COX-2 expression and angiogenesis of lung cancer is yet to be delineated. Eighty four non-small cell lung cancer (NSCLC) specimens were evaluated for COX-2 expression, microvessel density (MVD), and vascular endothelial growth factor (VEGF) expression by immunohistochemical methods. The relationships between COX-2 expression and MVD, VEGF expression, and survival time were analyzed.