Article
Chemistry, Multidisciplinary
Elias Ferreiro-Vila, Juan Molina, Lukas M. Weituschat, Eduardo Gil-Santos, Pablo A. Postigo, Daniel Ramos
Summary: This study demonstrates a new method for high-resolution room temperature thermal measurement using nanomechanical resonator-free standing silicon nitride membranes, achieving unprecedented results. In a high vacuum environment, the heat transfer mechanisms of the devices are limited to thermal conductivity and radiation.
Article
Physics, Applied
Katsuhiko Nishiguchi, Hiroshi Yamaguchi, Akira Fujiwara, Herre S. J. van der Zant, Gary A. Steele
Summary: We have demonstrated charge detection with single-electron resolution at high readout frequency using a silicon field-effect transistor integrated with double resonant circuits. The transistor, with a channel width of 10 nm, can detect a single electron at room temperature. The transistor is connected to resonant circuits composed of coupled inductors and capacitors, providing two resonance frequencies. By driving the transistor with a carrier signal at the lower resonance frequency, a small signal applied to the transistor's gate modulates the resonance condition, resulting in a reflected signal appearing near the higher resonance frequency. This operation allows for charge detection with a single-electron resolution of 3 x 10(-3) e/Hz(0.5) and a readout frequency of 200 MHz at room temperature.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Hongchang Qiao, Chenchang Zhan, Yutian Chen
Summary: This paper presents a picowatt CMOS voltage reference design with ultra-low power consumption and wide temperature range, achieved by biasing PMOS leakage current and utilizing bulk diode leakage current modulation effect. The experimental results demonstrate stable voltage reference performance under different conditions, showing good line sensitivity and temperature coefficient.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2021)
Article
Polymer Science
Akihiko Toda
Summary: The crystallization kinetics of poly(butylene terephthalate) under high supercooling was investigated using Temperature-Modulated Fast Scanning Calorimetry (TM-FSC). The study found a temperature dependence of crystal growth rate and compared it with the peak time of heat flow during isothermal crystallization. The crystal growth rate was found to be practically determined by a mobility factor near the glass transition.
Article
Computer Science, Hardware & Architecture
Hamed Aminzadeh, Mohammad Mahdi Valinezhad
Summary: A tiny-size ultra-low voltage CMOS voltage reference circuit with quiescent picoamp scale is proposed in this paper to meet the high standards of modern wireless microsystems. The circuit protects the sensitive core from power supply glitches via a temperature-dependent cascode current source, and has broadened output temperature range and low line-voltage sensitivity. Implemented in 0.18-mu m CMOS technology, the circuit consumes 690 pA from 0.3 V minimum supply voltage at room temperature and exhibits good performance in terms of output voltage, temperature coefficient, line-voltage sensitivity, and DC power supply ripple rejection.
INTEGRATION-THE VLSI JOURNAL
(2022)
Article
Multidisciplinary Sciences
Yong Zhao, Baoshuang Shang, Bo Zhang, Xing Tong, Haibo Ke, Haiyang Bai, Wei-Hua Wang
Summary: This study demonstrates that a Ce-based metallic glass can transform into a hyperstable state and exhibit strong resistance against crystallization after long-term aging. The achieved hyperstable state is similar to that of million-year-aged amber, and the Ce-based metallic glass can reach equilibrium liquid state below T-g without crystallization.
Article
Multidisciplinary Sciences
Aki Kitaori, Naoya Kanazawa, Tomoyuki Yokouchi, Fumitaka Kagawa, Naoto Nagaosa, Yoshinori Tokura
Summary: Research on emergent electromagnetic induction based on electrodynamics of noncollinear spin states has made progress in achieving large induction values at room temperature and above, which could be a significant step toward the development of microscale quantum inductors.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Chemistry, Multidisciplinary
Yuzhu Wang, Peng Wang, Hao Wang, Bingqian Xu, Hui Li, Mo Cheng, Wang Feng, Ruofan Du, Luying Song, Xia Wen, Xiaohui Li, Junbo Yang, Yao Cai, Jun He, Zhenxing Wang, Jianping Shi
Summary: An ingenious space-confined chemical vapor deposition strategy was used to synthesize atomically thin non-layered epsilon-Fe2O3 single crystals and revealed the room-temperature long-range ferrimagnetic order. Strong ferroelectricity and its switching behavior were discovered in atomically thin epsilon-Fe2O3, along with an anomalous thickness-dependent coercive voltage. The robust room-temperature magnetoelectric coupling was uncovered by controlling the magnetism with an electric field, demonstrating the multiferroic feature of atomically thin epsilon-Fe2O3. This work represents a substantial leap in the controllable synthesis of 2D multiferroics with robust magnetoelectric coupling, and also paves the way for practical applications in low-energy-consumption electric-writing/magnetic-reading devices.
ADVANCED MATERIALS
(2023)
Article
Multidisciplinary Sciences
Hariom Jani, Jheng-Cyuan Lin, Jiahao Chen, Jack Harrison, Francesco Maccherozzi, Jonathon Schad, Saurav Prakash, Chang-Beom Eom, A. Ariando, T. Venkatesan, Paolo G. Radaelli
Summary: In the quest for post-CMOS technologies, researchers have shown promising results in experimenting with topologically protected ferromagnetic whirls such as skyrmions and their anti-particles, which can serve as solitonic information carriers. Antiferromagnetic analogues have become the subject of intense focus due to their predicted relativistic dynamics and potential for fast deflection-free motion and size scaling, although experimental demonstration in natural antiferromagnetic systems has yet to be achieved. By utilizing a first-order analogue of the Kibble-Zurek mechanism, a family of topological antiferromagnetic spin textures has been stabilized on an Earth-abundant oxide insulator, showing potential for low-energy antiferromagnetic spintronics at room temperature.
Article
Chemistry, Multidisciplinary
Junning Li, Maria Barrio, David J. Dunstan, Richard Dixey, Xiaojie Lou, Josep-Lluis Tamarit, Anthony E. Phillips, Pol Lloveras
Summary: Barocaloric effects in a layered hybrid organic-inorganic compound (C10H21NH3)(2)MnCl4, which are reversible and colossal under pressure changes below 0.1 GPa, are reported. These effects are attributed to a phase transition characterized by features such as strong disordering of organic chains, a large volume change, high sensitivity of transition temperature to pressure, and small hysteresis. The obtained values are unprecedented for solid-state cooling materials at low pressure changes, indicating that colossal effects can be achieved in compounds other than plastic crystals.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Sergi Plana-Ruiz, Alejandro Gomez-Perez, Monika Budayova-Spano, Daniel L. Foley, Joaquim Portillo-Serra, Edgar Rauch, Evangelos Grivas, Dominique Housset, Partha Pratim Das, Mitra L. Taheri, Stavros Nicolopoulos, Wai Li Ling
Summary: Structural characterization is crucial for understanding protein function. Though electron crystallography can be performed on nanometer-sized crystals and provide additional information, its widespread use has been limited due to the fragility of such crystals. This work demonstrates a methodology to preserve these nanocrystals in their natural environment at room temperature for electron diffraction experiments.
Article
Nutrition & Dietetics
Katherine L. Ford, Claude Pichard, Michael B. Sawyer, Claire F. Trottier, Ilana Roitman Disi, Sarah A. Purcell, Sunita Ghosh, Mario Siervo, Nicolaas E. P. Deutz, Carla M. Prado
Summary: This study aimed to assess TEE in cancer patients, identify its predictors, and compare it with cancer-specific predicted energy requirements. The results showed that absolute TEE was higher in males, patients with colon cancer, and patients with obesity. TEE was lower than predicted requirements, indicating the need for improved assessment of energy requirements in cancer patients.
AMERICAN JOURNAL OF CLINICAL NUTRITION
(2023)
Article
Chemistry, Physical
John J. Flynn, Zachary M. Marsh, Douglas M. Krein, Steven M. Wolf, Joy E. Haley, Erick S. Vasquez, Thomas M. Cooper, Nicholas P. Godman, Tod A. Grusenmeyer
Summary: Lithocholic acid has been identified as a suitable host material for room temperature phosphorescent chromophores. Through differential scanning calorimetry (DSC) analysis, it was found that lithocholic acid and beta-estradiol can form stable molecular glasses, while cholesterol and beta-sitosterol cannot. The d(10)-pyrene in lithocholic acid molecular glasses has a longer lifetime and higher phosphorescence quantum yield compared to beta-estradiol molecular glasses.
Article
Nanoscience & Nanotechnology
O. J. Amin, S. F. Poole, S. Reimers, L. X. Barton, A. Dal Din, F. Maccherozzi, S. S. Dhesi, V. Novak, F. Krizek, J. S. Chauhan, R. P. Campion, A. W. Rushforth, T. Jungwirth, O. A. Tretiakov, K. W. Edmonds, P. Wadley
Summary: Researchers have discovered that topological spin textures can be generated and moved at room temperature using electrical pulses in the semimetallic antiferromagnet CuMnAs, which is a testbed system for spintronic applications. This finding is crucial for realizing the full potential of antiferromagnetic thin films as active components in high-density, high-speed magnetic memory devices.
NATURE NANOTECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Dong Hoon Shin, Hakseong Kim, Sung Hyun Kim, Hyeonsik Cheong, Peter G. Steeneken, Chirlmin Joo, Sang Wook Lee
Summary: In this study, a tri-layer graphene nanomechanical resonant mass sensor was fabricated using a bottom-up process, demonstrating sub-attogram resolution at room temperature. Joule heating was found to be effective in cleaning the graphene membrane surface and improving the stability of the resonance frequency. The sensor was characterized by depositing Cr metal and showed sufficient mass resolution for weighing very small particles, such as large proteins and protein complexes, with potential applications in nanobiology and medicine.
Article
Microbiology
Fuqiang Ma, Tianjie Guo, Yifan Zhang, Xue Bai, Changlong Li, Zelin Lu, Xi Deng, Daixi Li, Katsuo Kurabayashi, Guang-yu Yang
Summary: The study introduces a novel ultrahigh-throughput screening platform based on flow cytometric droplet sorting, which efficiently isolates new biocatalysts from metagenomic libraries and has the potential to significantly improve efficiency in exploring novel enzymes from nature.
ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Amin Reihani, Ju Won Lim, David K. Fork, Edgar Meyhofer, Pramod Reddy
Summary: The calorimetry of reactions involving nanomaterials is a current research focus, requiring high-resolution heat flow measurements and long-term thermal stability, especially at elevated reaction pressures and temperatures. An instrument for measuring the enthalpy of reactions between gas-phase reactants and milligram scale nanomaterial samples has been developed, with high calorimetric resolution and stability demonstrated through experiments involving H2 absorption on Pd nanoparticles. This study establishes the feasibility of performing high resolution calorimetry on milligram scale nanomaterials for future studies on catalysis, phase transformations, and thermochemical energy storage.
Article
Multidisciplinary Sciences
Tatyana E. Saleski, Meng Ting Chung, David N. Carruthers, Azzaya Khasbaatar, Katsuo Kurabayashi, Xiaoxia Nina Lin
Summary: The method presented in the study achieved tuning of pathway gene expression levels through random integration and high-throughput screening, leading to high productivity and yield of isobutanol in Escherichia coli. Examination of pathway expression in top-performing isolates highlighted the complexity of cellular metabolism and regulation, emphasizing the importance of precise optimization during integration of pathway genes into the chromosome.
Article
Physics, Applied
Amin Reihani, Shen Yan, Yuxuan Luan, Rohith Mittapally, Edgar Meyhofer, Pramod Reddy
Summary: This study presents a custom-fabricated scanning thermal probe (STP) that can accurately measure the temperature of microdevices at elevated temperatures. By introducing a modulated heat input and analyzing the different components of the STP temperature, the tip-to-sample thermal resistance and microdevice surface temperature can be simultaneously deduced.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Amin Reihani, Yuxuan Luan, Shen Yan, Ju Won Lim, Edgar Meyhofer, Pramod Reddy
Summary: The quantitative mapping of temperature fields with nanometric resolution is crucial in various scientific research areas and emerging technologies. Recent advances in scanning thermal microscopy (SThM) have enabled simultaneous quantification of tip-sample thermal resistance and topography, allowing for quantitative thermometry even in situations where the temperature field is modulated. The introduction of a modulated heat input to the scanning thermal probe (STP) allows for the mapping of unmodulated temperature fields with high spatial and temperature resolution, facilitating temperature mapping of microdevices under practical operating conditions.
Article
Materials Science, Composites
Minwoo Bae, Seungpyo Woo, Jae Min Lee, Woochul Lee, Sang-Hee Yoon
Summary: A theoretical model for the photopatternable thickness of photocurable PnCs containing carbon-based HAR fillers was established in this research, with its accuracy verified through experiments. Furthermore, the study extensively addressed the impact of filler content and UV exposure energy on the photopatterning error of photocurable PnCs containing carbon-based HAR filler.
COMPOSITES SCIENCE AND TECHNOLOGY
(2022)
Article
Optics
Amin Reihani, Edgar Meyhofer, Pramod Reddy
Summary: Ultrahigh-resolution thermometry is crucial for various fields including bio-calorimetry, sensitive bolometry, and probing dissipation in electronic, optoelectronic, and quantum devices. However, achieving high-resolution measurements from microscale devices at room temperature remains challenging. This study presents a band-edge microthermometer based on the temperature-dependent optical properties of GaAs, enabling high-resolution measurements.
Article
Physics, Multidisciplinary
Laura Rincon-Garcia, Dakotah Thompson, Rohith Mittapally, Nicolas Agrait, Edgar Meyhofer, Pramod Reddy
Summary: This article investigates the near-field radiative heat transfer phenomenon between metallic surfaces and finds that the heat transfer rate can exceed the far-field rate by over a thousand times at small gaps. The authors also show that the heat transfer rate saturates due to the dominant contributions from transverse electric evanescent modes at small gaps.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Anh Tuan Nguyen, Youlim Lee, Phuong Quang Hoang Nguyen, Przemyslaw Dera, Sang-Hee Yoon, Woochul Lee
Summary: By investigating the changes in graphite nanoflakes (GnFs) induced by gamma-ray irradiation, it is found that the electrical conductance exponentially increases while the interlayer spacing gradually decreases. Gamma-ray irradiation shows promise in tailoring the electrical properties of GnFs.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Physical
Suman Chhetri, Anh Tuan Nguyen, Sehwan Song, Nicolas Gaillard, Godwin Severa, Tianwei Ma, Sang-Hee Yoon, Woochul Lee
Summary: Researchers fabricated graphite nanoflake/polydimethylsiloxane nanocomposites with different concentrations, and found that the optimum concentration for maximum solar absorption was 3 wt%. The nanocomposite showed a total solar absorption of 94.8% and was used to develop a floatable interfacial water evaporator with a high evaporation rate and solar-vapor conversion efficiency.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Thi Kieu Ngan Pham, Edward Bruffey, Anh Tuan Nguyen, Ricardo A. Rivera-Maldonado, Ding-Yuan Kuo, Brandi Cossairt, Woochul Lee, Godwin Severa, Joseph J. Brown
Summary: This study successfully synthesized and deposited MgB2 thin films on a gold surface using a wet-chemistry colloid synthesis and deposition process, circumventing the extreme conditions of conventional physical deposition methods. Gas adsorption experiments, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) characterization were conducted to validate the functionality and obtain meaningful data of the deposited MgB2 films. A similar synthesis method was applied on an evaporated Au film on glass, and the film thickness was measured to be 3.9 nm using scanning transmission electron microscopy (STEM). AFM roughness measurements confirmed the successful mitigation of the coffee-ring effect.
Article
Chemistry, Multidisciplinary
Rohith Mittapally, Ju Won Lim, Lang Zhang, Owen D. Miller, Pramod Reddy, Edgar Meyhofer
Summary: Recent experiments have revealed that near-field radiative heat transfer (NFRHT) between objects separated by nanoscale gaps can significantly enhance heat transfer rates. Silicon dioxide (SiO2) surfaces, which support surface phonon polaritons (SPhP), demonstrate the most prominent enhancements. However, theoretical analysis suggests that SPhPs in SiO2 occur at frequencies much higher than optimal. In this study, we demonstrate theoretically that NFRHT mediated by SPhPs can be 5-fold larger for materials supporting SPhPs closer to the optimal frequency of 67 meV at room temperature. Furthermore, we experimentally show that MgF2 and Al2O3 closely approach this limit, with near-field thermal conductance between MgF2 plates separated by 50 nm reaching nearly 50% of the global SPhP bound. These findings lay the foundation for exploring the limits of radiative heat transfer rates at the nanoscale.
Article
Nanoscience & Nanotechnology
Ayan Majumder, Dakotah Thompson, Rohith Mittapally, Pramod Reddy, Edgar Meyhofer
Summary: Control of nanoscale thermal transport is crucial for various applications. Previous studies have suggested that enhanced heat transfer in planar membranes with nanoscale thickness is due to directional and spatially confined in-plane heat transfer. However, experimental evidence for this confinement is lacking. This study directly quantifies the spatial extent of heat transfer and provides detailed explanations for the observations, potentially leading to new approaches for active control of nanoscale heat flow.
Article
Nanoscience & Nanotechnology
Rohith Mittapally, Ju Won Lim, Edgar Meyhofer, Pramod Reddy, Bai Song
Summary: Recent measurements have shown that near-field radiative heat transfer (NFRHT) at the nanoscale is significantly different from far-field thermal radiation and can exceed the blackbody radiation limit by orders of magnitude. In this study, the thickness-dependence of NFRHT between planar nanofilms of magnesium fluoride was directly measured, demonstrating for the first time that nanofilms can enhance thermal radiation up to 800 times above the blackbody limit. Fluctuational electrodynamics calculations showed good agreement with the measured gap-size dependence, providing physical insight into the observed enhancement. These findings pave the way for exploring novel thin films in near-field thermal and energy systems.
Article
Nanoscience & Nanotechnology
Suman Chhetri, Anh Tuan Nguyen, Sehwan Song, Dong Hyuk Park, Tianwei Ma, Nicolas Gaillard, Sang-Hee Yoon, Woochul Lee
Summary: Carbon and semiconductor nanoparticles are promising photothermal materials. This study proposes a method to enhance the photothermal effect by using core-shell structures. The energy transfer effect in the core-shell structure can increase the photothermal conversion efficiency, making it promising for solar energy-driven applications.
ACS APPLIED MATERIALS & INTERFACES
(2023)
