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Recently, various bioelectronic nose devices based on human receptors were developed for mimicking a human olfactory system. However, such bioelectronic nose devices could operate in an aqueous solution, and it was often very difficult to detect insoluble gas odorants. Here, we report a portable bioelectronic nose platform utilizing a receptor protein-based bioelectronic nose device as a sensor and odorant-binding protein (OBP) as a transporter for insoluble gas molecules in a solution, mimicking the functionality of human mucosa. Our bioelectronic nose platform based on I7 receptor exhibited dose-dependent responses to octanal gas in real time. Furthermore, the bioelectronic platforms with OBP exhibited the sensor sensitivity improved by ∼100% compared with those without OBP. We also demonstrated the detection of odorant gas from real orange juice and found that the electrical responses of the devices with OBP were much larger than those without OBP. Since our bioelectronic nose platform allows us to directly detect gas-phase odorant molecules including a rather insoluble species, it could be a powerful tool for versatile applications and basic research based on a bioelectronic nose.

Diffusion-induced stresses in Sn, a promising anode material for Li-ion batteries owing to its high specific capacity, depend significantly on the phase transformation mechanism. In this study, an in-situ X-ray diffraction study is performed to reveal the phase transformation mechanism in Sn as functions of the discharge rate and Sn anode dimensions. In a 500 nm-thick Sn thin-film discharged at C/9 or a 100 nm-thick Sn thin-film discharged at 0.1C, the Sn phase transforms sequentially to Li2Sn5, followed by β-LiSn and a-Li7Sn3 in three steps, where each step involves reaction-controlled lithiation. However, in a 500 nm-thick Sn thin-film discharged at 2C or a 2 μm-thick Sn thin-film discharged at 0.1C, the a-Li7Sn3 phase is directly formed via one-step reaction-controlled lithiation between Sn and a-Li7Sn3. A transition from three-step to one-step results in a steep gradient in the mismatch strain, thereby causing early failure. Finite element simulations show a lower J-integral for the three steps compared with that of a one-step reaction, thereby confirming previously reported experimental observations. For a specified transformation mechanism, the J-integral is lower for smaller Sn micropillars. Therefore, the mechanical reliability of the Sn anode can be enhanced significantly when lithiated under phase transformation mechanism involving three-reaction-controlled lithiations, as well as utilizing a small Sn anode measuring less than 200 nm.

Binary metal sulfides have been explored as sodium storage materials owing to their high theoretical capacity and high stable cyclability. Nevertheless, their relative high charge voltage and relatively low practical capacity make them less attractive as an anode material. To resolve the problem, addition of alloying elements is considerable. Copper antimony sulfide is investigated as a representative case. In this study, we do not only perform electrochemical characterization on CuSbS2, but also investigate its nonequilibrium sodiation pathway employing in-/ex situ transmission electron microscopy, in situ X-ray diffraction, and density functional theory calculations. Our finding provides valuable insights on sodium storage into ternary metal sulfide including an alloying element.

The development of high-tap density electrode materials that can simultaneously achieve stable electrochemical performance at high charge/discharge rates is critically in demand. Herein, we propose an innovative material design that can offer high tap density and excellent rate capabilities by using Co3O4 nanograin-interconnected secondary particles (Co3O4 NISPs). By taking advantage of a conversion reaction that forms Co from Co3O4, we demonstrate that Co3O4 NISPs are capable of creating a number of metallic Co sites along with a number of vacant sites in-between nanograins. Electrochemical tests that reveal reduced internal cell resistance and more accessible Li diffusion are achieved for Co3O4 NISPs compared with Co3O4 nanoparticles (NPs). Additionally, in situ X-ray diffraction (XRD) analyses, electron energy loss spectroscopy (EELS), and density functional theory (DFT) calculations reveal that the insulating intermediate product (CoO) is formed less on the Co3O4 NISPs, which can enhance the charge transport. Attributed to the combinatorial effects of Co3O4 nanograins that form metallic Co upon conversion and secondary particles that enable high tap density, Co3O4 NISPs show the most outstanding volumetric capacity (2167.3 mA h cm−3 at a current density of 500 mA g−1) among spinel-type metal oxide electrode materials researched so far.

Antiferromagnetic spin waves have been predicted to offer substantial functionalities for magnonic applications due to the existence of two distinct polarizations, the right-handed and left-handed modes, as well as their ultrafast dynamics. However, experimental investigations have been hampered by the field-immunity of antiferromagnets. Ferrimagnets have been shown to be an alternative platform to study antiferromagnetic spin dynamics. Here we investigate thermally excited spin waves in ferrimagnets across the magnetization compensation and angular momentum compensation temperatures using Brillouin light scattering. Our results show that right-handed and left-handed modes intersect at the angular momentum compensation temperature where pure antiferromagnetic spin waves are expected. A field-induced shift of the mode-crossing point from the angular momentum compensation temperature and the gyromagnetic reversal reveal hitherto unrecognized properties of ferrimagnetic dynamics. We also provide a theoretical understanding of our experimental results. Our work demonstrates important aspects of the physics of ferrimagnetic spin waves and opens up the attractive possibility of ferrimagnet-based magnonic devices. Right- and left-handed spin-wave modes are identified in ferrimagnets, and their dynamics are revealed.

Graphene liquid cell transmission electron microscopy allows in situ observation of nanomaterial dynamics in a liquid environment. However, this method suffers from both random formation and small size of liquid pockets. Here, we introduce facile and mass-producible graphene-sealed well-type liquid cells with rational designs. The developed liquid cell structure and its formation mechanism depending on hole diameter (d)/spacer thickness (h) ratio are systematically analyzed. Finally, we show its high-resolution imaging and chemical analysis capability for nanoparticles and biomaterial applications. This work will provide an enhanced liquid cell platform for diverse liquid environmental studies.

The development of high performance and cost-effective electrode materials is the main challenge for the commercialization of sodium ion batteries. Here, we suggest a substantial iron-doped sodium vanadium fluorophosphate and sodium vanadium phosphate composite as a promising cathode. Iron substitution enhances ionic diffusivity and lowers the bandgap, and, thus, improves sodium storage performance. The origin of the enhanced performance is investigated employing in situ X-ray diffraction, ex situ X-ray photoelectron spectroscopy, density functional theory calculation, and electrochemical characterization. Moreover, we demonstrate its full cell configuration with earth-abundant element-based copper sulfide anodes. The suggested cathode and sodium ion battery full cell exhibits well-balanced sodium storage performance in terms of energy density, C-rate capability, cycling stability, and low cost. The low cost and high performance of the full cell make it an attractive choice for energy storage systems and high power applications to support lithium ion batteries.

Artificial Adaptive and Maladaptive Sensory Receptors In article number 2103484, Chong‐Yun Kang, Jung Ho Yoon, and co‐workers implement artificial adaptive and maladaptive sensory receptors using a diffusive memristor as a biological counterpart of the somatosensory system in all vertebrates. A new class of artificial receptor underlying surfacedominated switching dynamics successfully mimics key parameters of the biological receptor, including short‐latency, selective response, and tunability. [Image: see text]

Binary metal sulfides have been explored as sodium storage materials owing to their high theoretical capacity and high stable cyclability. Nevertheless, their relative high charge voltage and relatively low practical capacity make them less attractive as an anode material. To resolve the problem, addition of alloying elements is considerable. Copper antimony sulfide is investigated as a representative case. In this study, we do not only perform electrochemical characterization on CuSbS

As it governs the overall performance of lithium-ion batteries, understanding the reaction pathway of lithiation is highly desired. For Co3O4 nanoparticles as anode material, here, we report an initial conversion reaction pathway during lithiation. Using graphene liquid cell electron microscopy (GLC-EM), we reveal a CoO phase of the initial conversion product as well as morphological dynamics during Co3O4 lithiation. In accordance with the in situ TEM observation, we confirmed that the Co3O4 to CoO conversion is a thermodynamically favorable process by calculating the theoretical average voltage based on density functional theory. Our observation will provide a useful insight into the oxide electrode that undergoes conversion reaction.

Spin-orbit coupling effect in structures with broken inversion symmetry, known as the Rashba effect, facilitates spin-orbit torques (SOTs) in heavy metal/ferromagnet/oxide structures, along with the spin Hall effect. Electric-field control of the Rashba effect is established for semiconductor interfaces, but it is challenging in structures involving metals owing to the screening effect. Here, we report that the Rashba effect in Pt/Co/AlOx structures is laterally modulated by electric voltages, generating out-of-plane SOTs. This enables field-free switching of the perpendicular magnetization and electrical control of the switching polarity. Changing the gate oxide reverses the sign of out-of-plane SOT while maintaining the same sign of voltage-controlled magnetic anisotropy, which confirms the Rashba effect at the Co/oxide interface is a key ingredient of the electric-field modulation. The electrical control of SOT switching polarity in a reversible and non-volatile manner can be utilized for programmable logic operations in spintronic logic-in-memory devices.

Spin-orbit torque (SOT) has been studied extensively in a heavy-metal (HM)/ferromagnet (FM) bilayer structure, where a HM is an essential ingredient because a spin current is generated via the spin Hall effect within the HM layer and/or the Rashba-Edelstein effect from the HM/FM interface. Here, we report the observation of SOT in a ferrimagnetic $\mathrm{Tb}\text{\ensuremath{-}}\mathrm{Co}$ single layer with perpendicular magnetic anisotropy without a HM layer. Using harmonic Hall voltage measurements, we investigate the SOT-induced dampinglike effective field $({B}_{\mathrm{DL}})$ in a $\mathrm{Tb}\text{\ensuremath{-}}\mathrm{Co}$ layer; the sign of ${B}_{\mathrm{DL}}$ is opposite from that of a $\mathrm{Pt}/\mathrm{Tb}\text{\ensuremath{-}}\mathrm{Co}$ bilayer, and the magnitude of ${B}_{\mathrm{DL}}$ increases as the $\mathrm{Tb}\text{\ensuremath{-}}\mathrm{Co}$ composition approaches its magnetization compensation point. Moreover, we analyze the elemental composition of $\mathrm{Tb}\text{\ensuremath{-}}\mathrm{Co}$ as a function of film thickness using scanning transmission electron microscopy and electron energy-loss spectroscopy, indicating that the sign and magnitude of the SOT are virtually insensitive to the vertical composition gradient within the $\mathrm{Tb}\text{\ensuremath{-}}\mathrm{Co}$ layer. Our results demonstrate that the bulk spin-orbit interaction within the $\mathrm{Tb}\text{\ensuremath{-}}\mathrm{Co}$ layer itself plays a major role in generating SOT in a $\mathrm{Tb}\text{\ensuremath{-}}\mathrm{Co}$ single layer.

Understanding of lithium polysulfide (Li-PS) formation and the shuttle phenomenon is essential for practical application of the lithium/sulfur (Li/S) cell, which has superior theoretical specific energy (2600 Wh/kg). However, it suffers from the lack of direct observation on behaviors of soluble Li-PS in liquid electrolytes. Using in situ graphene liquid cell electron microscopy, we have visualized formation and diffusion of Li-PS simultaneous with morphological and phase evolutions of sulfur nanoparticles during lithiation. We found that the morphological changes and Li-PS diffusion are retarded by ionic liquid (IL) addition into electrolyte. Chronoamperometric shuttle current measurement confirms that IL addition lowers the experimental diffusion coefficient of Li-PS by 2 orders of magnitude relative to that in IL-free electrolyte and thus suppresses the Li-PS shuttle current, which accounts for better cyclability and Coulombic efficiency of the Li/S cell. This study provides significant insights into electrolyte design to inhibit the polysulfide shuttle phenomenon.

A biological receptor serves as sensory transduction from an external stimulus to an electrical signal. It allows humans to better match the environment by filtering out repetitive innocuous information and recognize potentially damaging stimuli through key features, including adaptive and maladaptive behaviors. Herein, for the first time, the authors develop substantial artificial receptors involving both adaptive and maladaptive behaviors using diffusive memristor. Metal‐oxide nanorods (NR) as a switching matrix enable the electromigration of an active metal along the surface of the NRs under electrical stimulation, resulting in unique surface‐dominated switching dynamics with the advantage of fast Ag migration and fine controllability of the conductive filament. To experimentally demonstrate its potential application, a thermoreceptor system is constructed using memristive artificial receptors. The proposed surface‐dominated diffusive memristor allows the direct emulation of the biological receptors, which represents an advance in the bioinspired technology adopted in creating artificial intelligence systems.

Herein, the dynamics of oxidative etching of Ag nanoparticles in an ionic liquid is monitored in situ via graphene liquid cell transmission electron microscopy. The results reveal that hollow nanosphere formation occurs via a stepwise process involving shell formation and hollowing of the nanoparticle. In addition, we describe the different etching kinetics in each step.

Antiferromagnetic spin waves have been predicted to offer substantial functionalities for magnonic applications due to the existence of two distinct polarizations, the right-handed and left-handed modes, as well as their ultrafast dynamics. However, experimental investigations have been hampered by the field-immunity of antiferromagnets. Ferrimagnets have been shown to be an alternative platform to study antiferromagnetic spin dynamics. Here we investigate thermally excited spin waves in ferrimagnets across the magnetization compensation and angular momentum compensation temperatures using Brillouin light scattering. Our results show that right-handed and left-handed modes intersect at the angular momentum compensation temperature where pure antiferromagnetic spin waves are expected. A field-induced shift of the mode-crossing point from the angular momentum compensation temperature and the gyromagnetic reversal reveal hitherto unrecognized properties of ferrimagnetic dynamics. We also provide a theoretical understanding of our experimental results. Our work demonstrates important aspects of the physics of ferrimagnetic spin waves and opens up the attractive possibility of ferrimagnet-based magnonic devices.

The stress inevitably imposed during electrochemical reactions is expected to fundamentally affect the electrochemistry, phase behavior and morphology of electrodes in service. Here, we show a strong stress-composition coupling in lithium binary alloys during the lithiation of tin-tin oxide core-shell nanoparticles. Using in situ graphene liquid cell electron microscopy imaging, we visualise the generation of a non-uniform composition field in the nanoparticles during lithiation. Stress models based on density functional theory calculations show that the composition gradient is proportional to the applied stress. Based on this coupling, we demonstrate that we can directionally control the lithium distribution by applying different stresses to lithium alloy materials. Our results provide insights into stress-lithium electrochemistry coupling at the nanoscale and suggest potential applications of lithium alloy nanoparticles., Electrochemical reactions can generate stresses that detrimentally affect battery electrodes. Here, the authors directly image the lithiation of core-shell tin-based nanoparticles and show that lithium can be redistributed by applying stress and change the nanoparticle composition.

Fluid induced vibration in high-elevation tower and its piping system is examined with on-site measurement, numerical simulation, and analytical model. In this article, Amine regeneration tower in gas separation plant is subjected to investigation since significant vibration in both tower and its piping system prevents the normal operation especially with increased loading capacity. Measurement in frequency domain for inlet piping system shows single dominant peak as well as small peaks in low frequency range. In search of solution, analytical study with computational fluid dynamics model is conducted to reduce fluid velocity which results in decreased dynamic force in both piping system and regeneration tower and reduces the fluid-induced vibration associated with slug flow. Based on the fluid dynamics study, piping modification is designed and applied to the piping system and tower and vibration improvement is achieved as expected.

Acoustic-Mechanical coupling effect on piping dynamics is examined on site with measurement and analytical development. In this article, a multi-treater piping system in OCU (Olefin Conversion Unit) plant is subjected to investigation since significant piping vibration prevents the normal operation when some specific combinations of two treaters are operated. There is severe piping and structure vibration problem especially with increased capacity. Measurement in frequency domain shows two peaks so close each other to result in high amplitude in the piping system vibration by beating phenomenon. In search of solution, extra safety valve is manually opened to increase the acoustic volume which changes the acoustic natural frequency in the subjected piping system and decrease the vibration. Analytical study with acoustic analysis software is also conducted and it shows the same results as the actual piping dynamics. Based on the acoustic study, piping modification is designed and applied to the piping system and vibration improvement is achieved as expected.

In article number 1900264, Jong Min Yuk and co‐workers visualize four types of semi‐coherent boundaries formed during sodiation in copper sulfide utilizing high‐resolution transmission electron microscopy. The semi‐coherent boundaries do not only act as mechanical pillars for pulverization‐tolerance, but also provide additional sodium transport paths for capacity recovery. The novel sodiation mechanism enables exceptionally stable sodium storage in copper sulfide.

Finding suitable electrode materials is one of the challenges for the commercialization of a sodium ion battery due to its pulverization accompanied by high volume expansion upon sodiation. Here, copper sulfide is suggested as a superior electrode material with high capacity, high rate, and long‐term cyclability owing to its unique conversion reaction mechanism that is pulverization‐tolerant and thus induces the capacity recovery. Such a desirable consequence comes from the combined effect among formation of stable grain boundaries, semi‐coherent boundaries, and solid‐electrolyte interphase layers. The characteristics enable high cyclic stability of a copper sulfide electrode without any need of size and morphological optimization. This work provides a key finding on high‐performance conversion reaction based electrode materials for sodium ion batteries.

Morphological evolution accompanying a surface roughening and preferred orientation is an effective way to realize a high-performance gas sensor because of its significant potential as a chemical catalyst through chemical potentials and atomic energy states. In this work, we investigated a heterojunction of double-side-W-decorated NiO nanoigloos fabricated through radio frequency sputtering and a soft-template method. Interestingly, a morphological evolution characterized by a pyramidal rough surface and the preferred orientation of the (111) plane was observed upon decorating the bare NiO nanoigloos with W. The underlying mechanism of the morphological evolution was precisely demonstrated based on the van der Drift competitive growth model originating from the oxygen transport and chemical strain in the lattice. The gas sensing properties of W-decorated NiO show an excellent NO2 response and selectivity when compared to other gases. In addition, high response stability was evaluated under interference ga...

Transparent, flexible composite films with switchable haze are presented that respond stably and rapidly to applied bias. The composite film is based on the laminated structure of all flexible materials, such as the polyethylene terephthalate substrate, graphene, paraffin-polydimethylsiloxane (P-PDMS) organogel, and PDMS overlayer stacked in order. Upon applying a bias, the graphene is Joule-heated, leading a microstructural transformation of paraffin impregnated in the PDMS matrix, which in turn causes the modulation of light scattering. While the total transmittance is maintained above 90% in the visible range, transmission haze of the film can be controlled over the range from 0.5 to 85% with a low applied voltage and power consumption of 18 V and 0.33 W/cm 2 , respectively. Because of the presence of an over-coating layer of PDMS, stable and reliable operation of the composite film is achieved for number of switching cycles. The advent of a highly transparent optical film with haze controllability that is made possible by this work can be used as a diffusive film to enhance the light-trapping properties for photovoltaics, and attachable films with controllable clarity on a window for ensuring personal privacy.

Herein, the dynamics of oxidative etching of Ag nanoparticles in an ionic liquid is monitored in situ via graphene liquid cell transmission electron microscopy. The results reveal that hollow nanosphere formation occurs via a stepwise process involving shell formation and hollowing of the nanoparticle. In addition, we describe the different etching kinetics in each step.

Sodium ion batteries have been considered a promising alternative to lithium ion batteries for large-scale energy storage owing to their low cost and high natural abundance. However, the commercialization of this device is hindered by the lack of suitable anodes with an optimized morphology that ensure high capacity and cycling stability of a battery. Here, we not only demonstrate that copper sulfide nanoplates exhibit close-to-theoretical capacity (~560 mAh g–1) and long-term cyclability, but also reveal that their sodiation follows a non-equilibrium reaction route, which involves successive crystallographic tuning. By employing in situ transmission electron microscopy, we examine the atomic structures of four distinct sodiation phases of copper sulfide nanoplates including a metastable phase and discover that the discharge profile of copper sulfide directly reflects the observed phase evolutions. Our work provides detailed insight into the sodiation process of the high-performance intercalation–conversion anode material., Copper sulfide allows for high-performance sodium ion storage, yet its sodiation mechanism is poorly understood. Here, the authors examine the atomic structures of sodiated phases via in situ transmission electron microscopy, showing a non-equilibrium reaction pathway.

We report a noise mapping strategy for the reliable identification and analysis of noise sources in molecular wire junctions. Here, different molecular wires were patterned on a gold substrate, and the current-noise map on the pattern was measured and analyzed, enabling the quantitative study of noise sources in the patterned molecular wires. The frequency spectra of the noise from the molecular wire junctions exhibited characteristic 1/f2 behavior, which was used to identify the electrical signals from molecular wires. This method was applied to analyze the molecular junctions comprising various thiol molecules on a gold substrate, revealing that the noise in the junctions mainly came from the fluctuation of the thiol bonds. Furthermore, we quantitatively compared the frequencies of such bond fluctuations in different molecular wire junctions and identified molecular wires with lower electrical noise, which can provide critical information for designing low-noise molecular electronic devices. Our method provides valuable insights regarding noise phenomena in molecular wires and can be a powerful tool for the development of molecular electronic devices.

We report a switchable biochip strategy where enzymes were entrapped in conducting polymer layers and the enzymatic reaction of the entrapped enzymes was controlled in real-time via electrical stimuli on the polymer layers. This device is named here as a "bio-switch chip" (BSC). We fabricated BSC structures using polypyrrole (Ppy) with entrapped glucose oxidase (GOx) and demonstrated the switching of glucose oxidation reaction in real-time. We found that the introduction of a negative bias voltage on the BSC structure resulted in the enhanced glucose oxidation reaction by more than 20 times than that without a bias voltage. Moreover, because the BSC structures could be fabricated on specific regions, we could control the enzymatic reaction on specific regions. In view of the fact that enzymes enable very useful and versatile biochemical reactions, the ability to control the enzymatic reactions via conventional electrical signals could open up various applications in the area of biochips and other biochemical industries.

We report a successful development of a floating electrode-based DNA sensor with controllable responses. Here, metallic floating electrodes were fabricated to form Schottky barriers between carbon nanotubes and the floating electrodes. We showed that the sensor response could be enhanced by increasing the number of floating electrodes. We also analyzed the response of the sensors based on the Langmuir isotherm theory.

The influence of spectrally varying mount properties (including stiffness and damping) on the dynamics of powertrain motions is analytically examined. To overcome the deficiency of the direct inversion method (limited to only the frequency domain analysis), two methods are developed that describe the mount elements via a transfer function (in Laplace domain) or analogous mechanical model. New analytical formulations are verified by comparing the frequency responses with numerical results obtained by the direct inversion method (based on Voigt type mount model). Eigensolutions and transient responses of a spectrally varying mounting system are also predicted from new models. Based on complex eigenstructure, new coupling indices, including modal kinetic energy fractions, are defined for each method. Complex eigenvalue problem formulation with spectrally varying properties provides a closer match with measured natural frequencies than the real eigensolution with frequency-independent mounts. Given spectral variance in the mount properties, a simple roll mode decoupling scheme is suggested for the powertrain isolation system. Finally, an axiom for torque roll axis decoupling is provided by employing direct and adjoint eigenvalue problems.

In order to improve the deep drawability of aluminum and aluminum alloy sheets, it is desirable to increase the ND// component in their textures. The ND// component is known to develop in shear-deformed fcc alloy sheets. The equal-channel angular pressing (ECAP) is a process in which materials undergo approximately simple shear deformation. The deformation texture of ECAPed strips can change depending on process variables such as the texture of starting strips, the oblique angle, the number of pressing passes, and the shear direction. The deformation and deformation texture have been analyzed.

A study has been made of the deformation and recrystallization textures of 1050 Al alloy strips deformed by equal-channel angular pressing (ECAP) with oblique angles of 90° and 120°, varied pressing numbers, and shear directions. The deformation texture is most influenced by the last pressing pass. The deformation textures vary along the thickness, with the top surface layer developing textures closest to the ideal shear texture consisting of the {1 1 1}〈1 1 2〉, {1 1 1}〈1 1 0〉, and {0 0 1}〈1 1 0〉 orientations, while the bottom surface layer most deviated from the ideal shear texture. The annealing textures of sheets can be approximated by weakened deformation texture plus the {0 0 1}〈1 0 0〉 texture, whose density is roughly proportional to the density of the {0 0 1}〈1 0 0〉 component in the deformation texture. To understand the behaviors, the deformation was analyzed by finite element method, and the annealing textures were discussed based on the strain-energy-release-maximization model.

Several mounting system design concepts are conceptually used to decouple the engine roll mode though limited success has been observed in practice. One shortcoming of the existing theories or design methods is that they ignore non-proportional viscous damping in their formulations. It seems that the rigid-body vibrations are coupled whenever non-proportional damping is introduced to the mounting system even though the torque roll axis decoupling is still theoretically possible with proportional damping assumption. To overcome this deficiency, we re-formulate the problem for a non-proportionally damped linear system while recognizing that significant damping may be possible with passive (such as hydraulic) or adaptive mounts. The complex mode method is employed in our work and the torque roll axis decoupling paradigm is re-examined given mount rate ratios, mount locations and orientation angles as key design parameters. We derive a necessary axiom for a mode in the torque roll axis direction provided two eigenvalue problems, in terms of stiffness and damping matrices, are concurrently satisfied. Two numerical examples are chosen to examine both steady-state and transient responses and the extent of coupling or decoupling is quantified. Results show that the torque roll axis for a mounting system with non-proportional damping (under oscillating torque excitation) is indeed decoupled when one of the damped modes lies in the torque roll axis direction. Finally, eigensolutions are validated by using experimental data.

We developed a magnetically-refreshable receptor platform structure which can be integrated with quite versatile nano-biosensor structures to build reusable nano-biosensor chips. This structure allows one to easily remove used receptor molecules from a biosensor surface and reuse the biosensor for repeated sensing operations. Using this structure, we demonstrated reusable immunofluorescence biosensors. Significantly, since our method allows one to place receptor molecules very close to a nano-biosensor surface, it can be utilized to build reusable carbon nanotube transistor-based biosensors which require receptor molecules within a Debye length from the sensor surface. Furthermore, we also show that a single sensor chip can be utilized to detect two different target molecules simply by replacing receptor molecules using our method. Since this method does not rely on any chemical reaction to refresh sensor chips, it can be utilized for versatile biosensor structures and virtually-general receptor molecular species.

Piezoelectric and dielectric properties as functions of x and y mole ratio in yPb(ZrxTil-x)O(1-y)Pb(Mn1/3/Nb/2/3/)O, ceramics, PZT-PMN, are investigated for large displacement piezoelectric devices. From the experimental results, when y is 0.95 and x is 0.505, the piezoelectric and dielectric properties are maximum, that is, electromechanical coupling coefficient(kp), piezoelectric strain constant(d33/), permittivity(33/T//0/), and Curie temperature are 58 %, 272 pC/N, 1520 and about 350, respectively. Also, when y is 0.90 and x is 0.50, their properties are 56 %, 242 pC/N, 1220, and 290, respectively. As MgO dopant is added from 0 wt% to 1 wt%, kp increases to 63 % and Qm decreases to 500 at the MgO dopant of 0.1 wt%, and then kp decreases to 57 % as MgO is added.