This PDF file contains the front matter associated with SPIE Proceedings Volume 9434, including the Title Page, Copyright information, Table of Contents, Invited Panel Discussion, and Conference Committee listing.

There is a continuous need for the Department of Defense (DoD) and its associate weaponry supply organizations to consistently evaluate the usability of weapons that exhibit deteriorative characteristics over a period of time. Along the same lines, enhanced condition-based maintenance evaluation procedures are necessary to mitigate the risk and reduce the cost of catastrophic failure of varying inventories of military systems. One significant area of research is the verification of the existence of sufficient concentrations of propellant stabilizer in the motor of stored missiles. Results from developed apparatuses can help collect degradation information to establish indicators that the missile’s double-based solid propellant is still functional after long-term storage. Other mechanisms are being developed for the assessment of degradation in gun barrel rifling. The research outlined in this paper summarizes the Army Aviation and Missile Research, Development, & Engineering Center’s (AMRDEC’s) investigative approaches relative to the use of spectral-optical and acoustical methodologies for detecting deteriorations in both propellant and the apparatus that engages munitions. A spectral-optical sensing approach is presented that is based on distinctive light collecting optical fiber –based developments designed to detect the concentration of propellant ingredients. The use of diagnostic acoustic sensing mechanisms is delineated to include the use of commercially available transducer-based readers to collect information that is indicative of the distance that acoustic waves travel through weaponry components. In collaboration with several AMRDEC industry and academia supporters, this paper outlines sensing methods that are under consideration for implementation onto weapon systems. Conceptional approaches, experimental configurations, and laboratory results are presented for each initiative. Cost-savings and improved weaponry health monitoring capabilities are expected to derive from each sensing mechanisms.

Development of tactile sensing technology has promoted intelligent human-machine interaction and recently has evolved out as one of the most promising area of electronics. Tactile sensing is a milestone in this field as it can extend the detection mode of tactile sensor through air. In this paper, we fabricated a tactile sensor using cellulose nanocrystal modified with graphene by isocyanate grafting. The new material is transparent, ecofriendly and integrated the capability of tactile sensing with fast response, high stability and high reversibility. Various materials from conducting metals to a human hand were checked for tactile sensing capability. It is found that the fabricated sensor could detect a human hand at a distance up to 6 mm away from the sensor. Combining the results, the discrete, flexible dual-mode tactile sensor fulfilled the technical and operational objectives of this work .

This article presents the design of a miniature detection system and its associated signal processing electronics, which can detect and selectively recognize vapor traces of different materials in the air – including explosives. It is based on the array of surface-functionalized COMB capacitive sensors and extremely low noise, analog, integrated electronic circuit, hardwired digital signal processing hardware and additional software running on a PC. The instrument is sensitive and selective, consumes a minimum amount of energy, is very small (few mm³) and cheap to produce in large quantities, and is insensitive to mechanical influences. Using an electronic detection system built of low noise analog front-end and hard-wired digital signal processing, it is possible to detect less than 0.3ppt of TNT molecules in the atmosphere (3 TNT molecules in 10¹³ molecules of the air) at 25°C on a 1 Hz bandwidth using very small volume and approx. 10 mA current from a 5V supply voltage. The sensors are implemented in a modified MEMS process and analog electronics in 0.18 um CMOS technology.

To monitor hypertrophic scars in burnt skin we proposed and demonstrated a hybrid polymer/carbon tube-based flexible pressure sensor. To monitor the pressure on skin by measurement, we were focusing on the fabrication of a well-defined hybrid polydimethylsiloxsane/functionalized multi-walled carbon tube array formed on the patterned interdigital transducer in a controllable way for the application of flexible pressure sensing devices. As a result, the detection at the pressure of 20 mmHg is achieved, which is a suggested optimal value of resistance for sensing pressure. It should be noted that the achieved value of resistance at the pressure of 20 mmHg is highly desirable for the further development of sensitive flexible pressure sensors. In addition we demonstrate a feasibility of a wearable pressure sensor which can be in real-time detection of local pressure by wireless communication module. Keywords:

Football players are more to violent impacts and injuries more than any athlete in any other sport. Concussion or mild traumatic brain injuries were one of the lesser known sports injuries until the last decade. With the advent of modern technologies in medical and engineering disciplines, people are now more aware of concussion detection and prevention. These concussions are often overlooked by football players themselves. The cumulative effect of these mild traumatic brain injuries can cause long-term residual brain dysfunctions. The principle of concussion is based the movement of the brain in the neurocranium and viscerocranium. The brain is encapsulated by the cerebrospinal fluid which acts as a protective layer for the brain. This fluid can protect the brain against minor movements, however, any rapid movements of the brain may mitigate the protective capability of the cerebrospinal fluid. In this paper, we propose a wireless health monitoring helmet that addresses the concerns of the current monitoring methods - it is non-invasive for a football player as helmet is not an additional gear, it is efficient in performance as it is equipped with EEG nanosensors and 3D accelerometer, it does not restrict the movement of the user as it wirelessly communicates to the remote monitoring station, requirement of individual monitoring stations are not required for each player as the ZigBee protocol can couple multiple transmitters with one receiver. A helmet was developed and validated according to the above mentioned parameters.

Development of an optical neurotransmitter sensing device using nano-plasmonic probes and a micro-spectrometer for real time monitoring of neural signals in the brain is underway. Clinical application of this device technology is to provide autonomous closed-loop feedback control to a deep brain stimulation (DBS) system and enhance the accuracy and efficacy of DBS treatment. By far, we have developed an implantable probe-pin device based on localized field enhancement of surface plasmonic resonance on a nanostructured sensing domain which can amplify neurochemical signals from evoked neural activity in the brain. In this paper, we will introduce the details of design and sensing performance of a proto-typed microspectrometer and nanostructured probing devices for real time measurement of neurotransmitter concentrations.

Detection of drowsiness in drivers to avoid on-road collisions and accidents is one of the most important applications that can be implemented to avert loss of life and property caused by accidents. A statistical report indicates that drowsy driving is equally harmful as driving under influence of alcohol. This report also indicates that drowsy driving is the third most influencing factor for accidents and 30% of the commercial vehicle accidents are caused because of drowsy driving. With a motivation to avoid accidents caused by drowsy driving, this paper proposes a technique of correlating EEG and EOG signals to detect drowsiness. Feature extracts of EEG and blink variability from EOG is correlated to detect the sleepiness/drowsiness of a driver. Moreover, to implement a more pragmatic approach towards continuous monitoring, a wireless real time monitoring approach has been incorporated using textile based nanosensors. Thereby, acquired bio potential signals are transmitted through GSM communication module to the receiver continuously. In addition to this, all the incorporated electronics are equipped in a flexible headband which can be worn by the driver. With this flexible headband approach, any intrusiveness that may be experienced by other cumbersome hardware is effectively mitigated. With the continuous transmission of data from the head band, the signals are processed on the receiver side to determine the condition of the driver. Early warning of driver’s drowsiness will be displayed in the dashboard of the vehicle as well as alertness voice and sound alarm will be sent via the vehicle radio.

Real time sensing of localized electrophysiological and neurochemical signals associated with spontaneous and evoked neural activity is critically important for understanding neural networks in the brain. Our goal is to enhance the functionality and flexibility of a neural sensing and stimulation system for the observation of brain activity that will enable better understanding from the level of individual cells to that of global structures. We have thus developed a miniaturized electronic system for in-vivo neurotransmitter sensing and optogenetic stimulation amenable to behavioral studies in the rat. The system contains a potentiostat, a data acquisition unit, a control unit, and a wireless data transfer unit. For the potentiostat, we applied embedded op-amps to build single potential amperometry for electrochemical sensing of dopamine. A light emitting diode is controlled by a microcontroller and pulse width modulation utilized to control optogenetic stimulation within a sub-millisecond level. In addition, this proto-typed electronic system contains a Bluetooth module for wireless data communication. In the future, an application-specific integrated circuit (ASIC) will be designed for further miniaturization of the system.

Research into the use of DNA molecules as building blocks for nanoelectronics as well as nanosystems continues. Recently, our group has reported significant electrical conductivity in λ-DNA through direct and in-direct measurements involving high-aspect ratio electrodes that eliminate the effect of the substrate. Our results demonstrate that, at moderate to high frequencies, λ-DNA molecular wires show low impedance. In addition, to prove that the conductivity is indeed from DNA bridge, we studied the effect of temperature and UV irradiation on DNA molecular wires. The temperature results indicate that λ-DNA molecular wires have differing impedance responses at two temperature regimes: impedance increases between 4°C - 40°C, then decreases from 40°C to the melting point (~110°C) at which λ-DNA denatures resulting in a complete loss of current transduction. This hysteric and bi-model behavior makes DNA a candidate for nanoelectronics components such as thermal transistors and switches. The data from UV exposure experiments indicates decreased conductivity of λ-DNA molecular wires after UV exposure, due to damage to GC base pairs and phosphate groups reducing the path available for both charge hopping and short-range electron tunneling mechanisms. The lessons learned from these conductivity experiments along with our knowledge of different charge transport mechanisms within DNA can be applied to the design of synthetic molecular wires for the construction of nanoelectronic devices.

RNA molecules are very flexible in nature. This feature allows us to build various motifs which are essential in bionanotechnological applications. Based on our earlier developed models of RNA nanoclusters, in this contribution we analyze the structure and properties of RNA nanotubes in physiological solutions at different concentrations. Our major tool here is the molecular dynamics (MD) method that was implemented by using the NAMD and VMD packages, with which we study the structural and thermal properties of the nanotubes in physiological solutions. In particular, we have analyzed such characteristics as the Root Mean Square Deviation (RMSD), the radius of gyration, the number of hydrogen bonds per base pairs, and the radial distribution function (RDF) of a RNA nanotube at different concentrations of the physiological solution. Furthermore, the number of ²³Na⁺ and ³⁵Cl⁻ions around the nanotubes within the distance of 5 Å at two different concentrations has also been analyzed in detail. It has been found that the number of ions accumulated around the nanotubes within the particular distance is growing by small amount while the concentrations of the ²³Na⁺ and ³⁵Cl⁻ions are substantially increased.

Cellulose is one of abundant renewable biomaterials in the world. Over 1.5 trillion tons of cellulose is produced per year in nature by biosynthesis, forming microfibrils which in turn aggregate to form cellulose fibers. Using new effective methods these microfibrils can be disintegrated from the fibers to nanosized materials, so called cellulose nanocrystal (CNC) and cellulose nanofiber (CNF). The CNC and CNF have extremely good strength properties, dimensional stability, thermal stability and good optical properties on top of their renewable behavior, which can be a building block of new materials. This paper represents recent advancement of cellulose nanocrystals and cellulose nanofibers, followed by their possibility for smart materials. Natural behaviors, extraction, modification of cellulose nanocrystals and fibers are explained and their synthesis with nanomaterials is introduced, which is necessary to meet the technological requirements for smart materials. Also, its challenges are addressed.

Metamaterials are artificially engineered microstructures that have strong resonance behavior although their electrical size is very small. Meta-resonator (metamaterial resonator) antennas use the resonance of the metamaterials to reduce the size of radiators and design multiband antennas. A split-ring resonator (SRR) is a well-studied metamaterial structure which obtains negative permittivity and/or permeability in a narrow frequency region. In this paper, metamaterial structures and meta-resonator antennas are designed and simulated using a full wave simulator. 2D metaresonator antennas are fabricated by photolithography and 3D meta-resonator antennas are fabricated by LTCC (Low- Temperature Co-fired Ceramic) technique. A free space measurement system is used to characterize metamaterial samples. Several 2D/3D meta-resonator antennas with SRRs are described.

Plasmonic structures have been proposed for enhancing light absorption in thin film solar cells, for which insufficient light absorption is a limiting factor for further improvement of efficiency. The optical path of light in the absorber layer of a solar cell is increased due to the enhanced light scattering by plasmonic structures at resonance. This process involves two steps of energy conversion: light-electron and then electron-light. The first step couples optical energy into the kinetic energy of collective electron motions in plasmonic structures, forming oscillating current. This step is easy to implement as long as plasmonic structures are at resonance. The second step releases the energy from electrons to photons. An efficient release of photon energy is a must for solar cell applications and it is dependent on the two competing effects: light scattering and field localization that results in heat loss. Theoretical discussions and simulation work are provided in the paper. The scattering of light by a plasmonic structure is analyzed based on the antenna radiation theory. Three factors are found to be important for the efficiency of a plasmonic light trapping design: the radiation of each unit structure, the array factor and the energy feeding of the structure. An efficient plasmonic light trapping design requires proper considerations of all the three factors.

This paper reviews feasibility of piezoceramic-polymer composite, so called piezocomposite, materials for UUV sonar application. Focus is not only placed on high electro-acoustic transformation performance, also on mass productivity, which is achieved by introducing Powder Injection Molding(PIM) process. Theoretical piezocomposite design method is introduced with FEM verification. Samples, produced via PIM process, are tested and proved their feasibility as UUV sonar sensors.

Miniaturization of optical systems has promoted a revolution in lens technology and this emerging field has much interest for medical practitioners as well as electronic engineers. Tunable liquid lens capable of adjusting its focal length have special curiosity in this regard where in micro-scale actuators are often integrated. Here we demonstrate a lens consisting of a transparent elastomer liquid composite containing organo modified cellulose nanocrystals. The actuator with the working voltage of only up to 0.8kV was capable to produce an area expansion and thereby altering the curvature of the lens (focal length) reversibly in 5 seconds. The effect of filler concentration on optical property and dielectric behavior of the composites were also analyzed.

A novel design for the geometric configuration of honeycombs using a seamless combination of auxetic and conventional cores-elements with negative and positive Possion ratios respectively, has been presented. The proposed design has been shown to generate a superior band gap property while retaining all major advantages of a purely conventional or purely auxetic honeycomb structure. Seamless combination ensures that joint cardinality is also retained. Several configurations involving different degree of auxeticity and different proportions auxetic and conventional elements have been analyzed. It has been shown that the preferred configurations open up wide and clean band gap at a significantly lower frequency ranges compared to their pure counterparts. In view of existence of band gaps being desired feature for the phononic applications, reported results might be appealing. Use of such design may enable superior vibration control as well. Proposed configurations can be made isovolumic and iso-weight giving designers a fairer ground of applying such configurations without significantly changing size and weight criteria.

Dynamic effects of plasmon such as scattering with defect boundaries and oxygen impurities in the graphene oxide are investigated. Study of plasmon dynamics helps in understanding electronic, opto-electronic and biological applications of graphene based nanostructures. Tuning or control over such applications is made possible by graphene nanostructure engineering. We have modeled defects with increased smoothing of defect edge in graphene keeping area of the defect constant. Scattering of plasmons in graphene with defects is modeled using an electromagnetic field coupled inter-atomic potential approach with finite element discretization of the atomic vibrational and electromagnetic field degrees of freedom. Our calculations show π+σ plasmon red shifting under sharp defect edges whereas π plasmon show high extinction efficiency. Strong localization of electric fields near the sharp defect edges is observed. Observations on plasmons and its dynamics draws attention in designing novel optoelectronic devices and binders for bio-molecules.

Thermoelectric materials are very effective in converting waste heat sources into useful electricity. Researchers are continuing to develop new polymeric thermoelectric materials. The segregated-network carbon nanotube (CNT)- polymer composites are most promising. Thus, the goal of this study is to develop novel porous CNT -polymer composites with improved thermoelectric properties. The research efforts focused on modifying the surface of the CNT with magnetic nanoparticles so that heat was released when subjecting to an AC magnetic field. Subsequently, polymers covered on the surface of the CNT were crosslinked. The porous CNT -polymer composites can be obtained by removing the un-crosslinked polymers. Polydimethylsiloxane polymer was utilized to investigate the effect of porosity and electrical conductivity on the thermoelectric properties of the composites. This AC magnetic field-assisted method to develop porous carbon nanotube/polymer composites for application in thermoelectric materials is introduced for the first time. The advantage of this method is that the electrical conductivity of the composites was high since we can easily to manipulate the CNT to form a conducting path. Another advantage is that the high porosity significantly reduced the thermal conductivity of the composites. These two advantages enable us to realize the polymer composites for thermoelectric applications. We are confident that this research will open a new avenue for developing polymer thermoelectric materials.

Hypertension and hypertension associated cerebrovascular and cardiovascular diseases are on a rise. At-least 970 million people in the world and Seventy percent of the American adults are affected by high blood pressure, also known as hypertension. Even though blood pressure monitoring systems are readily available, the number of people being affected has been increasing. Most of the blood pressure monitoring systems require cumbersome approaches. Even the noninvasive techniques have not lowered the number of people affected nor did at-least increase the user base of these systems. Uncontrolled or untreated hypertension may lead to various cerebrovascular disorders including stroke, hypertensive crisis, lacunar infarcts intracerebral damage, microaneurysm, and cardiovascular disorders including heart failure, myocardial infraction, and ischemic heart disease. Hypertension is rated as the one of the most important causes of premature death in spite of the technical advances in biomedical technology. This paper briefs a review of the widely adopted blood pressure monitoring methods, research techniques, and finally, proposes a concept of implementing nanosensors and wireless communication for real time non-invasive blood pressure monitoring.

Radio Frequency (RF) consumer applications have boosted silicon integrated circuits (IC) and corresponding technologies. More and more functions are integrated to ICs and their performance is also increasing. However, RF front-end modules with filters and switches as well as antennas still need other way of integration. This paper focuses to RF front-end module and antenna developments as well as to the integration of millimeter wave radios. VTT Technical Research Centre of Finland has developed both Low Temperature Co-fired Ceramics (LTCC) and Integrated Passive Devices (IPD) integration platforms for RF and millimeter wave integrated modules. In addition to in-house technologies, VTT is using module and component technologies from other commercial sources.

The integration of biosensors with radio frequency (RF) wireless power transmission devices is becoming popular, but there are challenges for implantable devices in medical applications. Integration and at the same time miniaturization of medical devices in a single embodiment are not trivial. The research reported herein, seeks to review possible effects of RF signals ranging from 900 MHz to 100 GHz on the human tissues and environment. Preliminary evaluation shows that radio waves selected for test have substantial influence on human tissues based on their dielectric properties. In the advancement of RF based biosensors, it is imperative to set up necessary guidelines that specify how to use RF power safely. In this paper, the dielectric properties of various human tissues will be used for estimation of influence within the selected RF frequency ranges.

Inorganic-organic hybrid composite has attracted as its combined synergistic properties. Cellulose based inorganicorganic hybrid composite was fabricated with semiconductive nanomaterials which has functionality of nanomaterial and biocompatibility piezoelectricity, high transparency and flexibility of cellulose electro active paper namely EAPap. ZnO is providing semiconductive functionality to EAPap for hybrid nanocomposite by simple chemical reaction. Cellulose- ZnO hybrid nanocomposite (CEZOHN) demonstrates novel electrical, photoelectrical and electromechanical behaviors. This paper deals with methods to improve electromechanical property of CEZOHN. The fabrication process is introduced briefly, charging mechanism and evaluation is studied with measured piezoelectric constant. And its candidate application will be discussed such as artificial muscle, energy harvester, strain sensor, flexible electrical device.

In the past decade, several high-strength gels have been developed, especially from Japan. These gels are expected to use as a kind of new engineering materials in the fields of industry and medical as substitutes to polyester fibers, which are materials of artificial blood vessels. We consider if various gel materials including such high-strength gels are 3D-printable, many new soft and wet systems will be developed since the most intricate shape gels can be printed regardless of the quite softness and brittleness of gels. Recently we have tried to develop an optical 3D gel printer to realize the free-form formation of gel materials. We named this apparatus Easy Realizer of Soft and Wet Industrial Materials (SWIM-ER). The SWIM-ER will be applied to print bespoke artificial organs, including artificial blood vessels, which will be possibly used for both surgery trainings and actual surgery. The SWIM-ER can print one of the world strongest gels, called Double-Network (DN) gels, by using UV irradiation through an optical fiber. Now we also are developing another type of 3D gel printer for foods, named E-Chef. We believe these new 3D gel printers will broaden the applications of soft-matter gels.

In this paper, energy harvesting capability is examined by changing the width of cantilever beam and piezoelectric cellulose. It is started from hypothesis that if cantilever piezoelectric energy harvester with given width are split, it would increase power output due to the fact that the divided pieces have smaller damping ratio than the original single piece, in turn, they are supposed to vibrate with high amplitude at resonance frequency.

In the experiment, as a piezoelectric material, cellulose Piezo Paper is prepared with aluminum electrode deposition. By attaching the Piezo Paper on an aluminum beam, a cantilever type piezoelectric energy harvester is made. The given width of the beam is 5cm, and sets of Piezo Papers with different width and number of beams are made as, 5cm x 1, 2.5cm x 2, 1.66cm x 3, 1.25cm x 4, 1cm x 5 and 0.83cm x 6 beams. Cantilever beams are vibrated on a shaker at its resonance frequency and examined their electrical characteristics in terms of output voltage and current. The results are compared with the original beam of 5 cm wide.

Array haptic actuator to realize texture of button for virtue flight simulator is fabricated by using cellulose acetate (CA) film. The haptic actuator has independent 3 × 3 cells for identical vibration. Each cell consists of topside CA layer and bottomside CA layer with two pillars. Two ends of topside CA layer are fixed on the pillars similar with fixed end beam. By an electrostatic force in the presence of electric field, the topside CA layer vibrates. Each cell shows its resonance frequency peak in the capable frequency range of vibrotactile feeling from 100 Hz to 500 Hz. The acceleration performance is shown to be higher than vibrotactile threshold on wide frequency band from 100 Hz to 400 Hz.

This paper presents a preliminary study investigating the development of a new type of non-contacting torque sensor based on the mechanoluminescence (ML) of a microparticles, such as ZnS:Cu. Typically, applications of ML microparticles have been used in a stress sensor applications successfully, in which these particles are applied to realtime visualization of the stress distribution of cracks, impacts, and ML light generation. Kim et al. demonstrated their potentials of ML microparticles by successfully measuring the sinusoidal torque applied to a rotational shaft through the measurement of the ML intensity signature using a photomultiplier tube (PMT) sensor, which can be widely used in various industrial areas such as automotives, robotics, rotors, and turbines. To show their further potential applications, a cost-effective luminescence sensor and UV LEDs are integrated, and used for detecting the variation of ML intensity in this study. In addition, precision sinusoidal torque waveform with high frequency up to 15 Hz is used to investigate the frequency-dependent hysteresis phenomenon.

Organic-inorganic hybrid material based cellulose was synthesized by the sol-gel approach. The explosion of activity in this area in the past decade has made tremendous progress in industry or academic both fundamental understanding of sol-gel process and applications of new functionalized hybrid materials. In this present research work, we focused on cellulose–dopamine functionalized SiO₂/TiO₂ hybrid nanocomposite by sol-gel process. The cellulose-dopamine hybrid nanocomposite was synthesized via γ-aminopropyltriethoxysilane (γ-APTES) coupling agent by in-situ sol-gel process. The chemical structure of cellulose–amine functionalized dopamine bonding to cellulose structure with covalent cross linking hybrids was confirmed by FTIR spectral analysis. The morphological analysis of cellulose-dopamine nanoSiO₂/TiO₂ hybrid nanocomposite materials was characterized by XRD, SEM and TEM. From this different analysis results indicate that the optical transparency, thermal stability, control morphology of cellulose-dopamine-SiO₂/TiO₂ hybrid nanocomposite. Furthermore cellulose–dopamine-SiO₂/TiO₂ hybrid nanocomposite was tested against pathogenic bacteria for antimicrobial activity.

Iron oxide/cellulose nanocomposite film is fabricated by impregnation of iron oxide nanoparticles into a regenerated cellulose film. The crystal structure, chemical functional group, morphological analysis, thermal stability and mechanical properties of the nanocomposite films are investigated by the wide-angle X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mechanical pull test. The investigated results show that the iron oxide is interacted with hydroxyl groups of the regenerated cellulose film. The tensile strength and elastic modulus of iron oxide/cellulose films are significantly enhanced up to 39% and 57% of pristine regenerated cellulose film, respectively.

Previous work demonstrated for the first time the ability to epitaxially grow uniform single crystal diamond cubic SiGe (111) films on trigonal sapphire (0001) substrates. While SiGe (111) forms two possible crystallographic twins on sapphire (0001), films consisting primarily of one twin were produced on up to 99.95% of the total wafer area. This permits new bandgap engineering possibilities and improved group IV based devices that can exploit the higher carrier mobility in Ge compared to Si. Models are proposed on the epitaxy of such dissimilar crystal structures based on the energetic favorability of crystallographic twins and surface reconstructions.

This new method permits Ge (111) on sapphire (0001) epitaxy, rendering Ge an economically feasible replacement for Si in some applications, including higher efficiency Si/Ge/Si quantum well solar cells. Epitaxial SiGe films on sapphire showed a 280% increase in electron mobility and a 500% increase in hole mobility over single crystal Si. Moreover, Ge possesses a wider bandgap for solar spectrum conversion than Si, while the transparent sapphire substrate permits an inverted device structure, increasing the total efficiency to an estimated 30-40%, much higher than traditional Si solar cells. Hall Effect mobility measurements of the Ge layer in the Si/Ge/Si quantum well structure were performed to demonstrate the advantage in carrier mobility over a pure Si solar cell. Another application comes in the use of microelectromechanical devices technology, where high-resistivity Si is currently used as a substrate. Sapphire is a more resistive substrate and offers better performance via lower parasitic capacitance and higher film carrier mobility over the current Si-based technology.

Bi is the largest group V element and has a number of advantages in III-V semiconductor properties, such as bandgap reduction, spin-orbit coupling, a preserved electron mobility over III-V-N materials, and nearly ideal surfactant properties resulting in a surface smoothing effect on GaAs. However, the mechanism for this behavior is not well understood. Insight on the mechanism is obtained through study of the Bi-terminated GaAs surface morphology and atomic reconstructions produced via molecular beam epitaxy (MBE). Experimental scanning tunneling microscopy (STM) characterization of the Bi/GaAs surface reveal disordered (1x3), (2x3), and (4x3) reconstructions, often sharing the same reflective high-energy electron diffraction (RHEED) patterns. Roughness on the micron length scale decreases as the step widen, attributed to the concurrent increase of opposite direction step edges on the nanometer length scale. Corresponding cluster expansion, density functional theory (DFT), and Monte Carlo simulations all point to the stability of the disordered (4x3) reconstruction at finite temperature as observed in experimental STM. The effects of incorporated Bi are determined through epitaxial GaSbBi growth on GaSb with various Ga:Sb:Bi flux ratios. Biphasic surface droplets are observed with sub-droplets, facets, and substrate etching. Despite the rough growth front, X-ray diffraction (XRD) and Rutherford backscatter (RBS) measurements show significant Bi incorporation of up to 12% into GaSb, along with a concurrent increase of background As concentration. This is attributed to a strain auto-compensation effect. Bi incorporation of up to 10% is observed for the highest Bi fluxes while maintaining low surface droplet density.

The dynamic characteristics of smart composite laminates with partially debonded piezoelectric actuator are investigated in this work. The proposed work introduces an improved layerwise theory based mathematical modeling with the Heaviside unit step functions to allow the possible sliding of the in-plane displacements and jump of the out-of-plane displacements for the debonded area. The finite element implementation is conducted using the four-node plate element to derive the governing equation. The dynamic characteristics are investigated by the frequency domain and time domain. The influence of actuator debonding to the natural frequencies is subtler for such kind of smart composite structures. The debonding of piezoelectric actuator also decreases its actuation ability that is reflected in the magnitudes of the system response. The proposed method can well predict the responses of the smart composite laminates with actuator debonding failures and it could be applied to the further damage detection methods.

In this work, the fabrication of thin films mixed with cholesterol enzyme as recognition component is shown, using solgel technique. The film was deposited at one end of photonic crystal fiber (optrode), which was used as carrier medium of sol-gel matrix. The concentration of cholesterol in the test sample was determined by the use of transmittance. Measuring device consists of a power source (laser diode), optrode and a light detector. The laser beam is transmitted through the optrode; the variations of intensity depending on cholesterol concentration are emitted to be detected by a photoresistor.

This paper reports the experiment and finite element (FEM) simulation of an array type film haptic actuator. Haptic actuator was made of cellulose acetate films and adhesive tape separator between two films. For preparing 3×3 array haptic device, nine identical actuators were joined together. The purpose of an actuator is to create vibration feedback resulting from applied potential. Cellulose acetate based film actuator is suitable for transparent haptic devices because of its high dielectric constant, flexibility and transparency. The focus of this paper is to use a finite element model to simulate and analysis haptic actuator and verify that result with experiment. The reason of preferring ANSYS simulation is for the flexibility of modeling, time saving, post processing criteria and result accuracy.