This PDF file contains the front matter associated with SPIE Proceedings Volume 11590, including the Title Page, Copyright information, and Table of Contents.

Wearable and Mobile Healthcare Nanosystems will be presented with a focus on the implementation of various engineering principles in the conception, design, development, analysis and operation of biomedical, biotechnological, wireless systems and applications. The primary objective of this talk is to introduce the latest research topics and techniques in biomedical and nanomedical wearable wireless technologies. This talk also discusses the development and application of mobile wearable nano-bio health monitoring systems for telemedicine. Nanomaterials-based biosensors used to measure physiological signals, such as electrocardiogram (ECG), electroencephalogram (EEG), electromyogram (EMG), and electrooculogram (EOG) will be discussed with the latest developments in Neurocardiology. Techniques and methodologies for physiological signal processing and utilizing Smartphones as base stations are discussed. Cloud computing resources used for complex computations, such as feature extraction and automatic diagnosis will be discussed.

Stress in daily life has become a significant issue due to health risks. Because many sources of stress are unavoidable, management of stress is critical. Recent wearable devices, detecting physiological signals such as electrodermal activity, have been developed for quantitative and practical stress management assessment. However, they rely on a rigid and bulky system that is uncomfortable to wear during daily activities and has significant motion artifact issues. Here, we introduce a wireless skin-conformal bioelectronic system that evaluates daily stress management. Ultrathin, stretchable circuit system incorporated with a silicone elastomer enables a soft lamination on the skin, providing portable, continuous monitoring of stress. Printed, biocompatible nanomembrane electrodes on a breathable silicone tape provide long-term wearability and skin compatibility, enabling seamless monitoring of galvanic skin response at home with daily activities. Demonstration of stress management practice with human subjects shows the effectiveness of stress alleviation with a promising, non-invasive, and portable wearable system.

Stroke survivors commonly experience unilateral muscle weakness, which limits their engagement in daily activities. Bimanual training has been demonstrated to effectively recover coordinated movements among those patients. We developed a low cost telerehabilitation platform dedicated to bimanual exercise, where the patient manipulates a dowel to control a computer program. Data on movement is collected using a Microsoft Kinect sensor and an inertial measurement unit to interface the platform, as well as to assess motor performance remotely. Toward automatic classification of bimanual movements executed by the user, we test the performance of a linear and a nonlinear dimensionality reduction techniques.

A leading cause of death in the US is cardiovascular disease, of which approximately 44% are attributable to coronary artery disease. A minimally invasive procedure with stent placement has drastically improved the outcomes. However, there are still relatively high percentages of a life-threatening complication called "restenosis" (i.e., re-narrowing of a coronary artery). Here, we introduce an imperceptible nanostructured electronic stent that incorporates an ultrathin stretchable wireless sensor with a stent for continuous surveillance of restenosis along with neointimal proliferation and plaque deposition. The low-profile, nanomembrane capacitive strain sensor is constructed by the printing of conductive nanoparticles and polymers on a soft elastomeric membrane. This sensor is capable of detecting strains as low as 0.15% with a sensitivity of 3% per linear strain. The sensor performance is suitable to detect small alterations produced in the coronary artery with the progression of restenosis under typical pulsatile flow. In addition, an in vitro testing platform has been developed to accurately evaluate the sensor's performance. Both numerical analysis and computational fluid dynamics (CFD) were used to design the artery model with various levels of restenosis. The strain plots of artery models from both numerical and computational analyses have successfully shown the relationship between the strain and restenosis levels, varied pressures, artery lumens, and artery thicknesses. Our recent outcomes will provide better solutions for both diagnostic heart disease and many other vascular diseases that require stents.

Contact pressure sensing and pressure mapping are commonly used in many automotive, healthcare, industrial, and robotics applications. Many commercially available pressure mapping solutions use a dense array of transducers embedded in a pad. However, the pad is relatively thick with noticeable rigid components, and high-resolution pressure mapping systems can be complex, cumbersome, bulky, expensive, and not portable. Thus, the objective of this study was to validate pressure mapping using a commercial Smartfoam interrogated using an electrical impedance tomography (EIT) measurement strategy and algorithm. In addition, the sensitivity of the Smartfoam was enhanced by depositing on its surface a piezoresistive carbon nanotube-based thin film. EIT electrodes were installed along the foam boundaries, thereby eliminating the need for any electrodes or rigid objects on the foam and pressure mapping surface. A custom data acquisition system was employed to apply electrical current excitations while measuring the boundary voltage response across pairs of boundary electrodes. The boundary voltage datasets were used for solving the EIT inverse problem to reconstruct the conductivity distribution of the specimen. Controlled pressure mapping tests were performed by placing different weights of varying contact areas on different positions of the nanocomposite Smartfoam. The EIT results confirmed that the nanocomposite Smartfoam could resolve pressure hotspots at different locations, as well as different magnitudes of contact pressure applied. Real-time pressure mapping was successfully demonstrated, while pressure mapping resolution and accuracy were also characterized. Overall, the system is lightweight, low-profile, and does not use rigid components on the foam surface. Future work will align this method for targeted consumer and healthcare applications.

The field of wearable electronics is a rapidly growing market with applications in medical monitoring, safety, and security. NextFlex has worked on the development of several prototype wearable systems for safety and security. The manufacturing of these devices at NextFlex does not use standard copper flex technology but rather utilizes printed silver inks leading to an additive manufacturing process that results in both a lighter-weight and more conformal design. NextFlex will give an overview of its efforts to create devices that can be integrated into clothing and will include the latest data on the reliability testing of the units.

Motivated by previous successes in the development of two-dimensional (2D) based electronic nose, we investigate the potential application of metal-decorated phosphorene-based sensor for detection of formaldehyde using density functional theory (DFT) and nonequilibrium Green’s function (NEGF) methods. The most stable adsorption configurations, adsorption sites, adsorption energies, charge transfer, and electronic properties of formaldehyde on the pristine and Pd-decorated phosphorene are studied. Our results indicate that formaldehyde is chemisorbed on Pd-decorated phosphorene via strong covalent bonds, and quick recovery time (3.58 sec) under UV exposure and at the temperature of 350 K, suggesting its potential application for gas sensors. The results reveal that Pd-decorated phosphorene can detect formaldehyde with high sensitivity of 3.8 times greater than pristine phosphorene. Our results demonstrate the potential application of phosphorene for detection of formaldehyde as an important lung cancer biomarker.

Twin-screw extruder (TSE) based additive manufacturing technology can effectively print high viscous materials into precise and complex shapes. The dimensional accuracy and quality of the printed parts depend on the correct selection of the extruder machine's processing parameters to the printing materials. Hence, this paper presents an experimental study on optimizing the processing parameters of TSE for high concentration nanocellulose paste. The optimized parameters include twin-screw speed, feeding rate, printing speed to the nozzle diameter, and nanocellulose paste concentration. The feed rate of 1.2 ml/min, screw speed of 150 rpm, and the printing speed of 9.37 mm/s were the optimum process parameters for high accuracy and high-quality 3D printed structures 25wt% nanocellulose paste. Furthermore, pyramid-shaped and star-shaped structures were printed to verify the optimized parameters.

In this paper, the performances of the capacitance characteristics of the Fused Deposition Modeling (FDM) 3D-printed pressure sensor was evaluated. The FDM 3D printing sensor is composed of flexible-material thermoplastic polyurethane and a conductive PLA (carbon black conductive polylactic acid) polymer. While 3D printing, polymer filaments heat up quickly before being extruded and cooled down quickly. Polymers have poor thermal conductivity, so the heating and cooling cause unevenness, which then results in internal stress on the printed parts due to the rapidity of the heating and cooling. The results validate that the capacitance measurement of 3D-printed pressure sensor is unstable due to internal stress before annealing. Therefore, annealing was performed to eliminate the instability of repeat measurement mismatch. In comparison to non-annealed sensor, the annealed sensor demonstrates that thermal annealing removes residual stress on the sensor, so the repeated measurement capacitance precision of the sensor somewhat stable. The results of this study will be very useful for the fabrication of various devices that employ 3D-printed sensor that have multiple degrees of freedom and is not limited by size and shape.

The development of high-strength nanocellulose long-fiber (CLF) has been required for future composite faced with environmental concerns as well as energy efficiency and biocompatibility towards the high value-added industry. To meet the demand, our research group has studying not only the top-down process, such as the isolation and characterization of nanocellulose from wood pulp, also the bottom-up process which is a continuous fabrication of CLF based on the nanocelluloses. Moreover, high-strength CLF was made via nanocellulose alignment technique by wet spinning and physical stretching. However, the specific modulus and specific strength of currently available CLFs are away behind the technical requirement. Thus, to enhance the mechanical properties, a chemical approach based on increased intermolecular binding through cross-linking induction is attempted with the existing continuous fabrication process. The process parameters and chemical reactions are experimentally investigated, and their effects are evaluated by chemical and mechanical analysis.

In this study, we developed a new type of cross-linked polyvinyl alcohol (PVA)-lignin i.e., esterified PVA-CA-lignin resin by using citric acid (CA) cross-linker. Firstly, hydrogen bonded PVA-CA-lignin resin was prepared by the mixing of PVA, lignin and CA and then esterification of hydrogen bonded PVA-CA-lignin resin was carried out at 180oC. Subsequently, the esterification of PVA-CA-lignin resin was confirmed by FTIR and the morphology of the esterified PVA-CA-lignin resin was examined with the help of scanning electron microscopy.Finally, the effects of CA cross-linker on the properties of esterified PVA-CA-lignin resin, especially the tensile strength and thermal stability were evaluated and analyzed. The results demonstrated that CA was cross-linked in PVA-lignin resin matrix and the content of CAenhances the performance of esterified PVA-CA-lignin resin significantly. The esterified PVA-CA-lignin resin is applicable for the natural fibre reinforced composites.

Molybdenum disulfide (MoS₂) is a two-dimensional material which has demonstrated semiconducting behavior [1]. Different kinds of irradiations create the defects in molybdenum disulfide (MoS₂) structure, different types of irradiations modulate the density of sulfur vacancies in MoS₂[1]. MoS₂ based and other 2-D materials-based devices and sensors are used in harsh environments [1]. In [2] authors have demonstrated studies of gamma irradiation on mono layer graphene. To develop and fabricate the MoS₂-based devices and sensors, nanoelectronics instrumentation such as Transmission Electron Spectroscopy (TEM), Scanning Electron Microscopy (SEM), Raman Spectroscopy, X-ray Photo-Electron Diffraction (XPS) techniques are required for characterization of MoS₂. Moreover, these radiation techniques, have huge impacts on electronic and optical properties of MoS₂ [3]. So, it is important to study irradiation effects on the crystal structure and properties of MoS₂. In this work, Co-60 source was used for the irradiation, which has nominal irradiation dose 2.07 Gy/min (207 rad/Min) (±5%). We have irradiated gamma-rays on four samples of single-layer molybdenum disulfide over copper substrate. We exposed the irradiation dose of 1.0 kGy (100 krad), 1.75 kGy (175 krad), 2.65 kGy (265 krad) and 3.0 kGy (300 krad) of irradiations on sample number one, two, three and four respectively. Through the Raman Spectroscopy, we studied E¹_2g, A_1g peaks. A_1g peak is at 403.6 cm^-1 and E¹_2g peak is at 384.7 cm^-1 in pristine MoS₂ Raman spectroscopy. Raman spectroscopy is nondestructive tool for characterization of S vacancies in MoS₂.

Electroactive artificial muscles has drawn special attention for potential engineering applications, such as biomedical active devices, haptic-feedback systems, wearable soft electronics, and soft micro-robotics. However in the field of bioinspired soft robotics, to accomplish sophisticated tasks as human fingers, electroactive artificial muscles are under development. Because, most of the exiting soft actuators show lack of high bending displacements with irregular response characteristics under low input voltages due to instabilities of active electrode materials under operation. This situation necessitates for the development of totally brand new functional electrode materials with enormous stability under prolonged electro-chemical exposures. The developed electrode materials based on pre-designed functional covalent organic frameworks and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) show promising actuation characteristics under low electric stimuli towards real-field soft robotics. The proposed artificial muscles can readily be operated on fragile display to make a soft touch similar to real human finger and can successfully accomplishes precise sophisticated tasks such as controlling personal folders and swiping pages of online books, and playing music apps.

Solid polymer electrolytes (SPEs) are suitable materials for the growth of flexible and compact supercapacitors. Flexible Ionic Polymer Metal Composites fabricated utilizing platinum (Pt) or Gold (Au), are studied for their applicability as Solid Polymer Electrolyte membranes for high--power supercapacitors, as they have shown improved performance as electronic devices. In this study, the fabrication of an all-solid-state supercapacitor which uses a Nafion membrane is investigated for its capacity and cycle life. In order to verify the reliability and properties of the all-solid-state supercapacitor, cyclic voltammetry and charge-discharge tests are performed.

Latest technologies regarding portable and wearable electronics greatly values their diverse form factors in a view of mechanically deformability. In detail, global companies are scrambling to release their first bendable, rollable and foldable electronics to the world as soon as possible. However, there exists some inevitable issues regarding shape-deformable batteries that makes it hard to develop a truly deformable electronics. In order to overcome current drawbacks, herein, a high-strength intertwined nanosponge reinforced solid-state polymer electrolyte is reported that can be readily applied to highly bendable, rollable, and foldable lithium-ion batteries (LIBs). Thoroughly engineered Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) based intertwined nanosponge which has high porosity yet tightly entangled structure, to be used as reinforcement for polymer electrolyte. Along with the high mechanical strength that the entangled structure possesses, high porosity in intertwined nanosponge attributed to facile impregnation of ion-conducting electrolyte, thus, forming robust conjugation of two different functional components into one enhanced solid-state polymer electrolyte. Most importantly, intertwined nanosponge and ion-conducting polymer electrolyte were separately prepared, followed by direct conjugation to preserve high mechanical strength and superior ionic conductivity of each respectively; after which the solid-state electrolyte gained merits of each components. As a result, the intertwined nanosponge solid-state polymer electrolyte manifested superior mechanical strength, superior ionic conductivity. Finally, real-time application to highly deformable LIBs was successfully demonstrated without any short-circuit or failure.

Triboelectric nanogenerators (TENGs) for harvesting mechanical energy are attracting significant research interest due to their simple mechanism and high power density which introduce them as promising device for small size and portable smart electronics. Developing green TENGs by application of biodegradable and biocompatible materials for harvesting energy is required for the current modern society. However, compared with synthetic materials, the biomaterials generate rather lower charge by contact electrification and improving of output power of bio-TENGs still remains a challenge. Cellulose, the most abundant biopolymer, is a strong, light-weight, flexible, and durable sustainable material that can be used for TENG fabrication. In this study, we introduced diatom bio-silica as a biomaterial additive to enhance the output performance of cellulose-based TENG. Having a highly porous three dimensional (3D) structure decorated with features at nanoscale, large surface area, abundancy, and low price make diatom frustule an excellent candidate material for bio-TENGs. Diatom frustule-nanocellulose bio-composite is mechanically strong, electron-rich, and low-cost and frictionally rough which enhanced the output performance of bio-TENGs. In addition, cytotoxicity study and s biocompatibility test on rabbit skin suggested that the diatom frustule-nanocellulose composite was biologically safe. Moreover, a practical application of the DF-CNF TENG was examined with a self-powered smart mask for human breathing monitoring.

Infrared (IR) wavelengths are applied in various fields such as detection of invisible matter which can generate irradiative energy from its body as well as analysis of chemical structures and materials, atmospheric observation, military, and medical. Atmospheric stagnation and continuous inflow of pollutants are introduced because of the extreme climate change caused by the increase in air pollutants such as greenhouse gases (GHGs) and particulate matter (PM). As a result, air pollutants are increasingly concentrated, but the technology to measure them is limited based on the current point of care. Satellite remote sensing by IR wavelength bands in Earth’s orbit can overcome points of care and track their changes. It is also one of the approaches that can effectively monitor the distribution of GHGs such as carbon dioxide and methane and PM simultaneously in real-time because of high spatial and temporal resolution. It is expected to estimate the causes of induction and increase of GHGs with comparative accuracy, and many countries adopt this measurement method. Furthermore, it can sufficiently complement the onsite network as it can measure changes in GHGs and PM relatively accurately in most of the earth, including areas that are difficult to access, unlike ground and air-based measurement techniques that can only observe in limited areas. This article summarizes the current research and issues applying satellite remote sensing technology for measuring them, especially GHGs, based on the IR spectrum and hyper-spectral method for analyzing acquired data.

Visual impairment represents a critical challenge for our society with 285 million affect worldwide; alarmingly, the prevalence is expected to triple by 2050. Supporting mobility is a chief priority for assistive technologies. In recent years, the integration of computer vision and haptic technologies has led to a number of wearable electronic travel aids (ETAs). Previously, we have proposed an ETA comprised of a computer vision system and a wearable haptic device in the form of a belt. The belt encompasses a two-by-five array of piezoelectric-based macro-fiber composite (MFC) actuators, which can generate vibrations on the abdomen when an oscillating voltage is applied across their electrodes. The computer vision system identifies position and distance of surrounding obstacles egocentrically and drives the actuators relative to the salience of the potential hazard(s). Despite promising pilots, the design, control, and optimization of the ETA requires substantial, potentially high-risk, and tedious training and testing to accommodate patient-specific behavioral idiosyncrasies and a variety of visual impairments. To address these issues, we employ a virtual reality (VR) platform that offers simulations of visual impairment by disease type and severity with front-end control. We review our early work on the first three visual impairments piloted in the platform, each with three levels of severity: mild, moderate and severe. The VR environment is interfaced with the ETA, which provides feedback to the user based on the position of virtual obstacles. These simulations allow safe, controlled, repeatable experiments with ETAs that can be performed with varying degrees of visual perception. Our framework can become a paradigm for the development and testing of ETAs, with other potential applications in disability awareness, education, and training.

Cellulose, a natural fiber, has been employed vastly for structural components due to its high mechanical strength and young’s modulus. The hydrophilic hydroxyl groups on the surface of cellulose nanofiber enables formation of cellulose-based nanocomposites with high mechanical properties which has been widely studied. The interfacial bonding of the composites between cellulose and other polymers could be improved further by surface modification of cellulose. Aiming to improve the mechanical properties of cellulose nanofiber and its composites as well as functional properties, a bio-inspired approach to coating polydopamine onto cellulose nanofiber was developed. Due to strong adhesion ability and self-polymerization of dopamine in tris buffer, polydopamine could be easily coated on cellulose nanofiber under mild conditions. Prefabricated cellulose nanofiber film and filament were modified by coating with polydopamine. FTIR, XPS, SEM confirmed a homogeneous polydopamine coating on cellulose nanofiber film and filament. The mechanical strength and stiffness of the cellulose-polydopamine fiber and the respective composite materials were investigated. The photostability, antibacterial, and electrical properties of the polydopamine-cellulose nanofiber were also studied.

Over the past decades, glass has been utilized in optoelectronic devices. However, glass has many limitations impeding its use including high coefficient of thermal expansion, glare and shadowing effects. Moreover, various complex nanostructures and inorganic nanoparticles are required to tune the optical properties of glass. For green optoelectronics, cellulose, the most ubiquitous and abundant polymer on planet, is the perfect candidate that could substitute glass. Herein, we modulate light propagation through a random network of cellulose fibers by dramatically tuning the optical properties of cellulose for different applications. We obtained a nano-paper with a high total transmittance >90% and an ultralow haze>0.5% which is suitable for high definition displays. By modifying the morphology of the same cellulose fibers, highly transparent and hazy cellulose film suitable for antiglare windows and solar substrates with a total transmittance >85% and haze >80% is also obtained. These findings offer new possibilities of using cellulose nanofiber to tune the optical properties of glass and other optical materials through blending or coating rather than using toxic nanoparticles.

Triboelectric nanogenerators (TENGs) can be utilized as power sources of wearable devices because of flexibility, light weight and cost effective devices. However, materials utilized in the wearable devices should be carefully selected to avoid side effects to the human body. In this work, we developed a chitosan-diatom (CD) composite film for triboelectric nanogenerators(TENGs) and fabricated a skin-attachable motion sensor. The CD film was composed of the chitosan and diatom silica. All of materials are biomaterials which cannot cause side effects. The biocompatible diatom silica embedded in the chitosan film enhanced the positive charge density of the chitosan film. The CD film was assembled with the fluorinated ethylene propylene (FEP) film for a contact and separation TENG. The maximum instantaneous power density was 468 mW/m2, which was 3.5 times higher than the chitosan film. Furthermore, the skin-attachable motion sensor was developed base on the CD TENG. We believe this work can provide the simple and safe way to increase the performance of biocompatible TENGs for wearable devices.

Quantitative measurements of human movements can drastically change how coaches, trainers, and clinicians tailor physical training, teach new athletic skills, and prescribe treatment for musculoskeletal injuries, such as ankle sprains. The gold standard for movement characterization today is optical motion capture, which uses an array of fixed high-resolution cameras to track markers mounted on a moving body. However, optical motion capture is inconvenient outside a laboratory and susceptible to movement artifacts such as skin and clothing/shoe deformation. Thus, this study aimed to develop a field-deployable, skin-mounted, skin-strain sensor that can accurately quantify skin strains while measuring muscular engagement during functional movements. The approach was to directly integrate piezoresistive graphene nanocomposites with commercial kinesiology tape to form a self-adhesive skin-strain sensor that could be mounted virtually anywhere on the body, such as the ankle-foot complex. Unlike optical motion capture and electronic textiles, “Motion Tape” can be worn underneath garments and within the shoe, directly measure skin-strains, and are insensitive to movement artifacts. This work began with fabricating Motion Tape using a scalable spray-coating method. The cyclic strain sensing properties were characterized through extensive load frame tests. Then, controlled experiments using test coupons and human studies were performed to compare the Motion Tape sensing response versus optical motion capture during a series of representative movements. Besides showing comparable sensing results, densely distributed skin-strain monitoring using Motion Tape was demonstrated using an electrical impedance tomography measurement strategy and algorithm. The distributed strains induced during dorsiflexion and plantarflexion of the ankle-foot complex were successfully characterized.

The "gold standard” of treatment for areas of significant bone loss involves using autologous bone grafts harvested directly from patients. However, these grafts have a complication rate of 10 to 40% during harvest and can only be harvested in limited quantities; this drives the research for alternative bone scaffold materials, such as polymers. Polypyrrole (PPy) is a biocompatible polymer with useful electrical properties that can be harnessed for bone healing. PPy has been shown to hold and release charged drug molecules according to changes in localized pH. A natural change in pH around areas of bone regeneration can act as a trigger for this polymer. Resins comprised of poly(ethylene) glycol (PEG) and PPy nanoparticles (NP’s) with entrapped fluoresceine (FL) were 3D printed using stereolithography techniques. This novel resin formulation was able to achieve a repeatable minimum XY feature resolution of 200 μm with a 25 μm layer thickness. Drug release testing showed a linear trend favouring larger FL release in more alkaline environments with an average release of 46.0 ± 6.0 μg FL release per gram of PPy NP’s incorporated into the resin at pH 8 over a 14-day period (n = 3). These tests show success of a biocompatible PPy/PEG polymer blend capable of being 3D printed for potential use in patient customized bone scaffolds. The pH sensitive drug release from PPy validates that it can be successful in areas of natural bone regrowth to release molecules that help promote healing.

Traditional wireless sensors with bulky batteries require battery replacement or wireless charging which are not suitable for in vivo applications. Also, the leakage of battery chemicals is highly risky. Battery-free sensors are relatively small and easy to maintain. In this paper, the magnetic induction-based Near-Field Communication (NFC) is employed to charge and communicate with intra-body sensors. Cell phones with NFC modules can be leveraged as readers to interact with in vivo sensors. In this way, the system does not require additional external wireless devices. The collected health-related data can be processed by cell phones directly. The in vivo sensors are powered up by using magnetic induction-based wireless energy transfer and health-related data are transmitted by sensors using backscatter communications. This paper introduces the system architecture and associated wireless simulations and empirical results. The inhomogeneous human body is considered using a layered-media model. Electromagnetic simulations are performed in COMSOL Multiphysics to study the communication range with signals from 100 kHz to 100 MHz in various environments. The results provide guidelines on the design of in-vivo battery-free sensors in terms of power consumption, coil size, and implanted depth.

This paper presents the preliminary study on new optical pressure sensor based on a Fabry-Perot interferometer (FPI) combined with mechnoluminescence diaphragm, which emits mechnoluminescent light when mechanical stimulation (in this study, alternating pressure) is applied. The FPI is a superposition of light reflected by two parallel reflective surfaces (i.e.: thin mirrors) and shows the wavelength change due to cavity changes. The optical device is often called an interferometer which the distance between the two surfaces (i. e, resonance length) changes. Fiber-optic Fabry–Perot (FOPF) pressure sensor uses this interference phenomenon by attaching a flexible diaphragm at the end surface of interferometer. When the pressure is applied to the diaphragm, distance between the two surfaces inside FOFP sensor can change. As a result, the external pressure can be detected either by measuring these interferences using a spectrometer or by capturing using a camera module with image processing. In this study, we explore the possibility of using ML diaphragm made of SrAl2O4:Eu2+,Dy3+ (SAO) powder as new diaphragm. ML diaphragm is thin composite and can emit green mechanoluminescent light (520nm) when the alternating pressure is applied. Spectral response turned out to be then changed and related to the magnitude of applied pressure.

Electromagnetic shunt damping is a sensorless vibration control method that uses a single voice coil motor (VCM) and may also be used for energy harvesting. If an amplifier is used to control the current of a VCM, the current control law has the same function as a shunt circuit. In this paper, we focus on a current-controlled VCM and propose a new method that analyzes not only the performance of conventional shunt vibration control but also the energy consumption and the servo performance of current. From a numerical example, it was clarified that the energy was consumed without being regenerated if the PI gain with the maximum damping effect was used. There is a trade-off between the damping effect and energy regeneration.

Humanity has achieved landing on Moon in 1969 and now humanity is looking forward to land on extraterrestrial regions, for example, Mars. To reach the extraterrestrial regions, In-Situ Resource Utilization (ISRU) is regarded as one of the most significant concepts because current technologies could not afford enough propellants and others. Therefore, Moon ISRU is considered one of the most possible keys to reach Mars. In the ISRU, Oxygen is the most essential priority to get from Moon, so the possibility of ISRU with Moon soil is studied in this research using Chemical equilibrium with applications (CEAs) which is developed by the Nasa Glenn research center. The main concept is dissociating Moon soil with E-beam because most major components of Moon soil are composed of Oxygen. Simulation with CEAs is performed, firstly, instead of using E-beam in Moon atmosphere condition. In the program, some of Moon’s atmospheric elements were put in the reaction and Moon’s atmospheric condition was applied. With those conditions, the fraction of Oxygen was simulated by dissociating Moon soil in CEAs. Hence, this research shows the most proper conditions to generate Oxygen and even other ions and atoms. Furthermore, the ultimate goal of this Moon ISRU is shown in this research.

Measuring and analyzing local field potential (LFP) signals from basolateral amygdala (BLA), hippocampus (HPC) and medial prefrontal cortex (mPFC) may help understand how they communicate with each other during fear memory formation and extinction. In our research, we have formulated a computationally simple and noise immune instantaneous amplitude cross correlation technique which can deduce lead and lag of LFPs generated in BLA, HPC, and mPFC and the directionality of brain signals exchanged between regions. LFP signals are recorded using depth electrodes in the rat brain and cross correlation analysis is applied to theta wave signals after filtering. We found that rats resilient to traumatic conditions (based on post-stress rapid eye movement sleep (REM)) showed a decrease in LFP signal correlation in REM and non-REM (NREM) sleep cycles between BLA-HPC regions after shock training and one day post shock training compared to vulnerable rats that show stress-induced reductions in REM. It is presumed this difference in neural network behavior may be related to REM sleep differences between resilient and vulnerable rats and may provide clues to help understand how traumatic conditions are processed by the brain.

Electrical impedance tomography (EIT) is a rising and emerging imaging technique with great potential in many areas, especially in functional brain imaging applications. An EIT system with high speed and accuracy can have many applications to medical devices supporting in diagnosis and treatment of neurological disorders and diseases. In this research, EIT algorithms and hardware are developed and improved to increase reconstructed images' accuracy and decrease the reconstruction time. Due to multiplexer design limitations, EIT measurements are subject to strong capacitive effects from charging and discharging in switching cycles around 300 to 400 samples per 1280 samples (in 10 milliseconds sampling). We developed an algorithm to choose data in steady-state condition only selectively. This method improves the signal-to-noise ratio and results in better reconstruction images. An algorithm to effectively synchronize the beginning points of data was developed to increase the system's speed. This presentation also presents the EIT system's hardware architecture based on Texas Instruments Fixed-Point Digital Signal Processor - TMS320VC5509A, which is low-cost, high potential in popularity the community in the future. For high operation speed, we propose the EIT system used Sitara™ AM57x processors of Texas Instruments.

Ultrasonic transducer is a sensor that realizes the mutual conversion of ultrasonic and electrical signals, and it is widely used in quality inspection, biomedical imaging and other fields. Commonly used ultrasonic transducers have a small detection range and low sensitivity due to the diffraction of sound waves. Focused transducers are used to improve detection sensitivity. Unfortunately, focused transducers have narrow depth of field. Here, we developed a Bessel ultrasonic transducer for large depth of field by using conical acoustic lens. An acoustic lens is attached to a unfocused ultrasonic. And the acoustic lens is a cuboid prism with a concave cone on the bottom, made of fused silica. Similar to an axicon that can generate a Bessel beam, the Bessel ultrasonic transducer can produce nondiffracting Bessel ultrasonic beams. Therefore, extended depth of field with uniformly high resolution and high detection sensitivity can be obtained. We used COMSOL to simulate the transmission of ultrasonic field of the designed conical acoustic lens, and compare it with the spherical focused ultrasonic transducer. The results show that the depth of field of the Bessel ultrasonic transducer is about 8 times that of the conventional spherical focused ultrasonic transducer. And the depth of field of the Bessel ultrasonic transducer can be further adjusted by adjusting the cone angle of the conical acoustic lens. The Bessel ultrasonic transducer will help improve the capabilities of the ultrasound probe and expand its application range. For example, an ultrasonic probe with a large depth of field will expand the imaging depth of photoacoustic microscopy and enhance its ability in non-destructive testing.

Photoacoustic tomography is a new medical imaging technology with the advantages of high resolution, high contrast and high penetration depth. There are three common photoacoustic imaging methods in practical applications: photoacoustic microscopic imaging (PAM), photoacoustic computed tomography (PACT), photoacoustic tomography (PAE). As an important branch of photoacoustic imaging, photoacoustic microscopy combines high contrast of optical imaging with high resolution of ultrasonic imaging. In photoacoustic microscopy, acousto-optic coupling prism is a very important component, which is usually composed of irregular prism and spherical concave acoustic lens at the bottom. Its function is to carry out optical transmission and ultrasonic detection. The ultrasonic depth of field of spherical concave acoustic lens is limited. In order to overcome this defect, researchers propose to use conical concave acoustic lens to produce Bessel sound beam to realize large depth of field ultrasonic detection. But the conical concave acoustic lens affects laser focusing and imaging. In order to solve this problem, we propose an optimization method to eliminate the influence of conical concave acoustic lens on beam transmission. A calibration mirror is added to the acousto-optic coupling prism with conical concave acoustic lens at the bottom, and the deterioration of the cone concave acoustic lens to the beam transmission is eliminated by optimizing the surface shape and thickness of the calibration mirror by Zemax. The optimization effect is evaluated by analyzing the spot. The simulation results show that the optimization method can eliminate the influence of the conical concave acoustic lens on the beam transmission, make the focal point and the focal point keep the coaxial focus, and improve the detection efficiency of the photoacoustic signal. This work is of theoretical significance for the systematic study of large depth of field photoacoustic microscopy.

In recent years, photoacoustic imaging is a new imaging technology which combines the advantages of high resolution and rich contrast of optical imaging and high penetration depth of acoustic imaging. Therefore, photoacoustic imaging is widely used in biomedical fields, such as brain imaging, tumor detection and so on. As an important branch of photoacoustic imaging, photoacoustic microscopy imaging of optical resolution can reach the submicron level and can meet the needs of multi-scale imaging from cell to tissue. However, the strongly focused Gaussian beam is usually used in the traditional system of photoacoustic microscopy imaging of optical resolution, and so the depth of imaging is small, which makes it difficult to achieve fast imaging of large volume. In order to solve this problem, researchers have proposed many schemes, one of which is to use non-diffracted beams instead of Gaussian beams for imaging. As a nondiffracted beam, Bessel beam is applied to photoacoustic microscopy imaging of optical resolution in this study because it has the characteristic of large depth of field. However, in practice, the cost of building the system of photoacoustic microscopy imaging of optical resolution is high and its structure is complex, so there is an urgent need for the technology of virtual simulation for photothermal simulation analysis of the imaging system. In order to achieve this goal, a virtual simulation platform of photoacoustic microscopy imaging system of Bessel beam based on finite element analysis was built by using simulation software COMSOL Multiphysics. In COMSOL, the Bessel beam realized by compound axicon was constructed and then irradiated the human brain tissue. The propagation of the Bessel beam in the brain tissue was simulated by solving the diffusion equation. And the temperature changes of gray matter and blood vessel were obtained by solving the equation of biological heat transfer. This study is helpful to understand the propagation of Bessel beam in human brain and the interaction between them, and has a certain theoretical significance for the optical imaging of human brain.

As an emerging nondestructive imaging technology recently, photoacoustic imaging (PAI), which is based on photoacoustic effect, combines the advantages: the high resolution and contrast of optical imaging and the high penetration depth of acoustic imaging. Thereinto, as a branch of photoacoustic imaging, photoacoustic microimaging inherited the advantages of photoacoustic imaging. The unique focusing mode of photoacoustic microimaging can meet the requirements of higher resolution in biological imaging, thus, it gained extensive applications in medical science field. However, on account of using high numerical aperture objective lens strongly focus on Gaussian beam, traditional photoacoustic microimaging system has shallow depth of imaging field, and its transverse resolution and signal-to-noise ratio deteriorate rapidly outside the focal point, limiting the velocity of large volume imaging. Owing to solve these problems, in this paper, we build a simulation platform for Airy beam photoacoustic microscopy based on K-Wave simulation toolbox. This platform uses Airy beam to inspire initial Photoacoustic signal in large volume and K-Wave simulation toolbox to simulate the propagation, recording and reconstruction process of Photoacoustic signal. As nondiffraction beam, Airy beam features the capacity of large depth of field, thus, its application could reach the requirement of large depth of field imaging of Photoacoustic microscopy system. Measuring the performances of the constructed Photoacoustic microscopy system, we constructed three-dimensional imaging of the blood vessel. By simulating A-Scan, B-Scan and C-Scan, we measured the performances of this system, such as axial resolution, transverse resolution and depth of field. Meanwhile, the three-dimensional imaging of the vertically tilted fiber also verified the three-dimensional imaging capability of the Airy beam photoacoustic microscopy simulation platform. The establishment of the simulation platform has a significance for the theoretical research of photoacoustic microscopy and its application in biomedicine.

In recent years, photoacoustic imaging, an emerging nondestructive biomedical imaging technology, has shown great potential for early diagnosis of diseases with its advantages of highly sensitive optical contrast and high resolution. It is a hard project to collect a large number of pathological medical images by using photoacoustic imaging. How to compress large amounts of data, rapid transmission and storage of important value information has become an urgent problem to be solved. In this paper, build a virtual simulation platform for compressed sensing photoacoustic tomography by combining compressed sensing reconstruction algorithms with photoacoustic imaging based on the k-wave simulation toolbox. On the one hand, compressed sensing can reduce sample rates, accelerated the speed of imaging. On the other hand, it can modify the demands for hardware devices and facilitate to transmit and store of data. The k-wave simulation toolbox is used to build simulation models for simulating the propagation of photoacoustic fields, recording of photoacoustic signals, and image reconstruction. We validated the performance of the simulation platform by imaging the vascular network. The results show that the virtual simulation platform compressed sensing photoacoustic tomography can achieve high-quality photoacoustic imaging with less data. The virtual platform can provide theoretical guidance for the application of compressed sensing in photoacoustic imaging.