Advanced operation of heated fluidic resonators via mechanical and thermal loss reduction in vacuum.

For simultaneous and quantitative thermophysical measurements of ultrasmall liquid volumes, we have recently developed and reported heated fluidic resonators (HFRs). In this paper, we improve the precision of HFRs in a vacuum by significantly reducing the thermal loss around the sensing element. A vacuum chamber with optical, electrical, and microfluidic access is custom-built to decrease the convection loss by two orders of magnitude under 10 mbar conditions.

Massively parallel electro-optic sampling of space-encoded optical pulses for ultrafast multi-dimensional imaging.

High-speed and high-resolution imaging of surface profiles is critical for the investigation of various structures and mechanical dynamics of micro- and nano-scale devices. In particular, recent emergence of various nonlinear, transient and complex mechanical dynamics, such as anharmonic vibrations in mechanical resonators, has necessitated real-time surface deformation imaging with higher axial and lateral resolutions, speed, and dynamic range. However, real-time capturing of fast and complex mechanical dynamics has been challenging, and direct time-domain imaging of displacements and mechanical motions has been a missing element in studying full-field structural and dynamic behaviours.

Nanomechanical Sensing Using Heater-Integrated Fluidic Resonators.

Micro/nanochannel resonators have been used to measure cells, suspended nanoparticles, or liquids, primarily at or near room temperature while their high temperature operation can offer promising applications such as calorimetric measurements and thermogravimetric analysis. To date, global electrothermal or local photothermal heating mechanisms have been attempted for channel resonators, but both approaches are intrinsically limited by a narrow temperature modulation range, slow heating/cooling, less quantitative heating, or time-consuming optical alignment. Here, we introduce heater-integrated fluidic resonators (HFRs) that enable fast, quantitative, alignment-free, and wide-range temperature modulation and simultaneously offer resistive thermometry and resonant densitometry.

Correction to: Cellular and biomolecular detection based on suspended microchannel resonators.

[This corrects the article DOI: 10.1007/s13534-021-00207-7.].

PCA-based sub-surface structure and defect analysis for germanium-on-nothing using nanoscale surface topography.

Empty space in germanium (ESG) or germanium-on-nothing (GON) are unique self-assembled germanium structures with multiscale cavities of various morphologies. Due to their simple fabrication process and high-quality crystallinity after self-assembly, they can be applied in various fields including micro-/nanoelectronics, optoelectronics, and precision sensors, to name a few. In contrast to their simple fabrication, inspection is intrinsically difficult due to buried structures.

Cellular and biomolecular detection based on suspended microchannel resonators.

Suspended microchannel resonators (SMRs) have been developed to measure the buoyant mass of single micro-/nanoparticles and cells suspended in a liquid. They have significantly improved the mass resolution with the aid of vacuum packaging and also increased measurement throughput by fast resonance frequency tracking while target objects travel through the microchannel without stopping or even slowing down. Since their invention, various biological applications have been enabled, including simultaneous measurements of cell growth and cell cycle progression, and measurements of disease associated physicochemical change, to name a few.

Effect of seasonal succession of algal communities on fouling of MF membrane.

An emerging threat to membrane application is the seasonal proliferation of algae in water sources such as rivers, reservoirs and lakes. This study investigated the link between feed parameters and the membrane performance of a pilot-scale microfiltration (MF) plant for 7 months. The seasonal succession of algae in relation to temperature dynamics was monitored.

Complex Exercise Improves Anti-Inflammatory and Anabolic Effects in Osteoarthritis-Induced Sarcopenia in Elderly Women.

We investigated the effects of a 15-week complex exercise program on osteoarthritis and sarcopenia by analyzing anabolic effects and the impact on the activities of daily living (ADLs). Nineteen women aged ≥60 years with sarcopenia (SEG, n = 9) or diagnosed with osteoarthritis with sarcopenia (OSEG, n = 10) were enrolled and underwent an exercise program. Insulin-like growth factor 1 (IGF-1), irisin, myostatin, interleukin-10 (IL-10), and tumor necrosis factor alpha (TNF-a) levels were analyzed pre- and post-intervention.

Tailoring the Spectral Absorption Coefficient of aBlended Plasmonic Nanofluid Using a CustomizedGenetic Algorithm.

Recently, plasmonic nanofluids (i.e., a suspension of plasmonic nanoparticles in a base fluid) have been widely employed in direct-absorption solar collectors because the localized surface plasmon supported by plasmonic nanoparticles can greatly improve the direct solar thermal conversion performance.

Absorption characteristics of a metal-insulator-metal nanodisk for solar thermal applications.

Due to their ability to confine light in a sub-wavelength scale and achieve coherent absorption, plasmonic nanostructures have been intensively studied for solar energy harvesting. Although nanoparticles generating localized surface plasmon resonance (LSPR) have been thoroughly studied for application in a direct absorption solar collector (DASC), nanoparticles exciting magnetic polaritons (MP) for use in a DASC have not drawn much attention. In this work, we report a metal-insulator-metal (MIM) nanodisk that can excite MP peaks apart from the LSPR in the solar spectrum.

Intense Pulsed Light-Treated Near-Field Electrospun Nanofiber on a Quartz Tuning Fork for Multimodal Gas Sensors.

Accurate and portable gas sensors are required for environmental monitoring, locating leakages, and detecting trace chemical vapors or gases. Although many sensors have been developed, few can rapidly and selectively detect parts per million (ppm) concentration changes. In this work, we fabricate multimodal gas sensors by depositing a single nanocomposite fiber between the prongs of a quartz tuning fork (QTF).

Micropipette Resonator Enabling Targeted Aspiration and Mass Measurement of Single Particles and Cells.

This paper reports micropipette resonators, mechanical resonator-integrated micropipettes, which enable selective aspiration and mass measurement of particles or cells suspended in liquids with two orthogonal vibration modes. A custom pipette pulling system is built to provide power-modulated linear heating on a rotating glass capillary to make an asymmetric cross section with extended uniformity.A glass capillary is stretched with the custom puller, cut within the pulled region, polished, mounted on a machined metallic jig, and then coated with a metal.

Design of a Broadband Solar Thermal Absorber Using a Deep Neural Network and Experimental Demonstration of Its Performance.

In using nanostructures to design solar thermal absorbers, computational methods, such as rigorous coupled-wave analysis and the finite-difference time-domain method, are often employed to simulate light-structure interactions in the solar spectrum. However, those methods require heavy computational resources and CPU time. In this study, using a state-of-the-art modeling technique, i.

Soft and Deformable Sensors Based on Liquid Metals.

Liquid metals are one of the most interesting and promising materials due to their electrical, fluidic, and thermophysical properties. With the aid of their exceptional deformable natures, liquid metals are now considered to be electrically conductive materials for sensors and actuators, major constituent transducers in soft robotics, that can experience and withstand significant levels of mechanical deformation. For the upcoming era of wearable electronics and soft robotics, we would like to offer an up-to-date overview of liquid metal-based soft (thus significantly deformable) sensors mainly but not limited to researchers in relevant fields.

Optical Detection of Small Metabolites for Biological Gas Conversion by using Metal Nanoparticle Monolayers Produced by Capillary-Assisted Transfer.

Detection of small metabolites is essential for monitoring and optimizing biological gas conversion. Currently, such detection is typically done by liquid chromatography with offline sampling. However, this method often requires large equipment with multiple separation columns and is at risk of serious microbial contamination during sampling.

Super-contrast-enhanced darkfield imaging of nano objects through null ellipsometry.

We rediscover the null ellipsometry principle for an outstanding image-contrast enhancement method for darkfield imaging. Simply by adding polarizers, compensators, and a photodiode sensor to a conventional darkfield imaging system and applying the null principle, Si nano-cylinder structures as small as D20 nm (H20 nm) on non-patterned wafer, and gap defects as small as 14.6 nm and bridge defects as small as 21.

Direct-current triboelectricity generation by a sliding Schottky nanocontact on MoS multilayers.

The direct conversion of mechanical energy into electricity by nanomaterial-based devices offers potential for green energy harvesting . A conventional triboelectric nanogenerator converts frictional energy into electricity by producing alternating current (a.c.

Electrophoresis assisted time-of-flow mass spectrometry using hollow nanomechanical resonators.

This report discusses the first demonstration of electrophoresis assisted time-of-flow mass spectrometry using 'U' shaped hollow nanomechanical resonators (HNR). Capillary electrophoresis was coupled with the HNR based mass detection to overcome low ionic conductivity of channels embedded in the HNR preventing direct in-situ electrophoretic separation. The flow of analytes through the HNR was achieved by balancing the hydrodynamic pressure to override the electromotive force and inhibit the motion of analytes towards the anode for capillary electrophoresis.

Increase in brain activation due to sub-tasks during driving: fMRI study using new MR-compatible driving simulator.

Background: Several studies have used functional magnetic resonance imaging (fMRI) to show that neural activity is associated with driving. fMRI studies have also elucidated the brain responses associated with driving while performing sub-tasks. It is important to note that these studies used computer mouses, trackballs, or joysticks to simulate driving and, thus, were not comparable to real driving situations.

Pulled microcapillary tube resonators with electrical readout for mass sensing applications.

This paper reports a microfabrication-free approach to make hollow channel mass sensors by pulling a glass capillary and suspending it on top of a machined jig. A part of the pulled section makes simple contact with an actuation node and a quartz tuning fork (QTF) which acts as a sensing node. The two nodes define a pulled micro capillary tube resonator (PμTR) simply supported at two contacts.

Standoff Mechanical Resonance Spectroscopy Based on Infrared-Sensitive Hydrogel Microcantilevers.

This paper reports a highly sensitive and selective remote chemical sensing platform for surface-adsorbed trace chemicals by using infrared (IR)-sensitive hydrogel microcantilevers. Poly(ethylene glycol) diacrylate (PEG-DA) hydrogel microcantilevers are fabricated by ultraviolet (UV) curing of PEG-DA prepolymer introduced into a poly(dimethylsiloxane) mold. The resonance frequency of a PEG-DA microcantilever exhibits high thermal sensitivity due to IR irradiation/absorption.

Multifunctional hydrogel nano-probes for atomic force microscopy.

Since the invention of the atomic force microscope (AFM) three decades ago, there have been numerous advances in its measurement capabilities. Curiously, throughout these developments, the fundamental nature of the force-sensing probe-the key actuating element-has remained largely unchanged. It is produced by long-established microfabrication etching strategies and typically composed of silicon-based materials.

Hollow Microtube Resonators via Silicon Self-Assembly toward Subattogram Mass Sensing Applications.

Fluidic resonators with integrated microchannels (hollow resonators) are attractive for mass, density, and volume measurements of single micro/nanoparticles and cells, yet their widespread use is limited by the complexity of their fabrication. Here we report a simple and cost-effective approach for fabricating hollow microtube resonators. A prestructured silicon wafer is annealed at high temperature under a controlled atmosphere to form self-assembled buried cavities.

Differences in and correlations between cognitive abilities and brain volumes in healthy control, mild cognitive impairment, and Alzheimer disease groups.

The purpose of this study is to investigate differences in and correlations between cognitive abilities and brain volumes in healthy control (HC), mild cognitive impairment (MCI), and Alzheimer's disease (AD) groups. The Korean Version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K), which is used to diagnose AD, was used to measure the cognitive abilities of the study subjects, and the volumes of typical brain components related to AD diagnosis-cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM)-were acquired. Of the CERAD-K subtests, the Boston Naming Test distinguished significantly among the HC, MCI, and AD groups.

Change of neuronal activations induced by the passive perception of driving speed difference.

The change of neuronal activation due to the passive perception of various driving speeds in comparison to a reference driving speed was assessed using functional Magnetic Resonance Imaging. Videos recorded in real driving conditions on the road at driving speeds of 50, 70, 90, and 110 km/h were shown as visual stimuli. An experiment consisted of three blocks, each having a control phase (50km/h) and a stimulation phase (70, 90, or 110 km/h).