This PDF file contains the front matter associated with SPIE Proceedings Volume 12045, including the Title Page, Copyright information, Table of Contents, and Conference Committee listings.

Chirped-pitch crossed surface relief gratings (CP-CSRGs) were fabricated on photoactive azobenzene thin films using a simple two-step procedure. The resulting gratings had a constant pitch in one direction and a varying (chirped) pitch in the orthogonal direction. They were coated with silver and tested for their ability to excite surface plasmon resonance (SPR). It was observed that incident light can be transmitted or blocked on different locations of the CP-CSRG device only as a function of the light’s wavelength. These SPR-based sensors were used to detect changes in the refractive index of aqueous sucrose solutions and a maximum sensitivity of 778.6 nm/RIU was obtained.

The number of people experiencing vision loss and visual impairment is continuously increasing, concurrently to the aging of the population. Wearable electronic travel aids (ETAs) can be used to realize assistive, intelligent navigation systems that overcome some of the problems that this disability brings about. We propose a virtual reality (VR) environment that can simulate orientation and mobility training with an ETA developed by our team, toward enhancing mobility skills in visually impaired people. VR simulations can serve as surrogates for physical environments that might be too dangerous to visit in person during the initial sessions of the training.

Many researchers are exploring the dielectric properties of the human body considering the increasing prevalence of mobile phone infrastructure. Using a cell phone for a long time may increase the risk of getting abnormality of human parts because the RFEME (radio frequency electromagnetic energy) emits electromagnetic radiation energy on humans. In the cell phone communications, a microstrip patch inside of the phone transmits electromagnetic radiation. As a result of mobile phone antenna radiation, human beings are exposed to electromagnetic field radiation every day. It is difficult to determine the long-term impact of radiation on the human body, because of the complexity of human anatomy. Several important variables are taken into consideration while evaluating the impact of antennas' radiation based on human body parts such as its permittivity, conductivity, depth of penetration, and specific absorption rates are being calculated using the available human’s properties, the temperature of selected human’s parts calculated using Penne’s bioheat equation. As is demonstrated in this purpose, we investigate the careful evaluation of the fundamental equation of relative permittivity, conductivity, specific absorption rate (SAR), and penetration depth (PD) also known as skin depth considering the widely available application of cell phones in GSM-phone innovation in 3G, 4G and 5G communications. To create the model, MATLAB is used for theoretical calculations for selected humans’ tissues.

A fabrication of aramid nanofibers (ANFs) based nanocomposite filaments and their mechanical characterization has been studied as preceding research for manufacturing high strength and modulus 3D structure. The fabrication process was designed by a homogeneous stirring of nanomaterials and wet spinning in the coagulant solution through a spinning nozzle. The aramid nanofibers were initially isolated from aramid fabric using deprotonation methods and used to prepare polyamide-imide (PAI) or cellulose nanofibers (CNFs) nanocomposites. The fabricated ANF/PAI nanocomposite filaments displayed Young’s modulus of ~ 13.6 GPa, and tensile strength of ~ 311.8 MPa. Moreover, the fabricated ANF/CNF nanocomposite filaments exhibited Young’s modulus of ~ 31.4 GPa, and tensile strength of ~ 353.6 MPa. This work shows that ANFs based nanocomposites are designed with simplified and cost-effective production to develop them into high-strength 3D printing materials.

The quest for bioderived resins and eco-friendly lightweight materials having remarkable mechanical performance is ubiquitous in scientific reports. In this work, we report a strong and tough biobased resin of esterified Polyvinyl alcohol-Citric acid-Lignin (E-PCL) suitable for nanocellulose fiber-reinforced polymer composites. The mechanical properties of the resin were optimized by varying the volumetric concentration of citric acid and subsequently esterified at 180°C. At 30% citric acid content, the esterified resin showed dramatic improvement in tensile strength (269.8%), toughness (1222.8%), Elastic modulus (273.5%), and hydrophobicity (48.5%). The adhesion strength of the resin to cellulose film was 31.92 MPa making it appropriate for green cellulose-based fiber-reinforced polymer composites. To validate our concept, three wet-spun nanocellulose filament was knit into mats on a loom and applied in composite fabrication through hand-layup and hot press. The lightweight yet strong and stiff structural composite displayed a record high flexural strength of 363.42 MPa and flexural modulus of 39.89 GPa with a water contact angle of 93.4°. Insights from this report offer a promising platform for utilizing environment-friendly resins and nanocellulose to engineer lightweight and robust structural composites for automotive, aerospace, and structural applications.

Developing robust bio-based composites against various kinds of petroleum-derived materials has necessitated the continuous exploration and utilization of natural fiber for high-performance applications, especially those derived from bio-sources. In this scenario, cellulose nanofiber (CNF) can be a vital alternative to replace synthetic fiber commonly used as CNF-reinforced composites. In this regard, we prepared lignin-derived vanillin epoxy resin through the epoxidation of vanillin, and it was cured with a 4,4’-diamino diphenyl methane hardener. Furthermore, the solvent-epoxy mixture was impregnated with CNF film to get the CNF-reinforced vanillin epoxy composites. To confirm the compatibility of epoxy with CNF, we performed FTIR spectroscopy. Further, the bending strength of nanocomposites was evaluated. This research could lead to the manufacture of high-performance and environmentally friendly natural fiber composites that can be potentially useable in numerous applications.

Maintaining the integrity of load-bearing webbing structures is crucial to ensure the safety of aerospace and aeronautical systems. Traditional sensing devices are not suited for strain sensing of webbing structures, due to their complexity and lack of flexibility. Here, we introduce a mechanochromic nylon webbing structure that exhibits fluorescence emission shifts in response to applied strains. The strain sensitivity of the webbing is quantified through tensile tests for a wide range of applied strains. The presented mechanochromic webbing could serve as load-bearing structures with non-destructive strain and damage sensing capabilities.

A unique feature of the space radiation environment is the presence of high-energy charged (HZE) particles which may pose a health risk to astronauts. One of the greatest concerns is the possibility of radiation-induced deterioration of central nervous system (CNS) functions. Past research using rodent models has revealed that radiation exposure led to unexpected alterations in behavior where executive functions are compromised which are vital for facilitating the attainment of mission success. This research aims to study CNS-related damage on male and female animal models following radiation exposure. However, exposure to HZE particles will inevitably introduce radiation-induced artifacts during the in-vivo electrophysiological recording process. To accurately correlate altered neural activity observed with changes in behavior, the On-line Tool for the Assessment of Radiation in Space (OLTARIS) will confirm the materials needed to fabricate neural probes since they must be developed to withstand extreme, HZE environments. Successful results will help scientists to understand the effect radiation has on hippocampal and prefrontal cortex regions of the CNS to prove the onset of behavioral impairments by direct neural sensing. This will open new paths for developing shielding and pharmaceutical countermeasures against cosmic radiation effects detected during deep space exploration.

Device size has now reached the nanoscale range due to advancements in technology and scaling in the fields of very large-scale integration. The single-electron transistor (SET) is a promising solid-state device that can provide an extension for Moore’s law and is suitable for next-generation nanoelectronics design and application. Due to the Coulomb oscillation properties of the SET in addition to the high gain and ultra-low power consumption of the tunnel field effect transistor (TFET), the implementation of the hybrid SET/TFET will primarily benefit high density (nanoscale), low-power integrated circuits (ICs), and fast switching devices. In this study, we present a hybrid model of a graphene-based single electron transistor [1] with an n-type double-gate graphene nanoribbon TFET structure [2] utilized as an integrator. For simplicity, the TFET is used in the shorted gate configuration by connecting both the front and back gates. Following this, we design a fourth order analog low pass filter using the integrator circuit of SET/TFET. With the implementation in SPICE and Matlab, we analyze the transfer function of our proposed filter from its frequency characteristics (Bode plot). Our findings reveal significant roll-off and, as a consequence, increased filtering functions with low power consumption. This study adds to the realization and implementation of SET/TFET into applications where high frequency contributes to the reliability, performance, and low power required for nanoscale devices and designs.

In the past few years, the demand for various types of medical endoscopes such as of gastroscopy, laryngoscopy, and bronchoscopy has been increasing significantly. The advancement of technology has not only created a demand for more accurate and precise medical endoscopes but also created a demand for a more compact and miniaturized medical endoscopes, which could ultimately reduce pain and discomfort for patients or even prevent perforation and infections in the worst-case scenarios. In this study, a Micro-Electro-Mechanical System (MEMS) optical scanner is presented as a new type of medical endoscope. This optical scanner device makes use of a lead-zirconate-titanate piezoelectric (PZT) ceramic film and a chemically etched tapered optical fiber to create a push-pull actuator. The push-pull actuator is then excited to drive the optical fiber as a detector to receive optical signal. The scanner device is fabricated by using photolithography processes to define patterns on our stainless-steel sheets, which will act as the substrate, and Aerosol Deposition (AD) method to deposit thin PZT films onto our stainless-steel sheets. Even though the scanner device is in its early stages of development, we were able to achieve various scanner patterns and motions by the proposed push-pull actuator. ANSYS finite element method was also used to not only provide a fair comparison to the practical results, but also used to design the required resonant frequency that can excite the push-pull actuator

Integral resonant control (IRC) is a vibration control method that measures the displacement of a flexible structure and positively feeds back the force generated by integrating the displacement. In the case of vibration control with IRC, the DC gain and the direct feedthrough term of the transfer function of a flexible structure have important roles for modeling and analysis. In the case of a piezoelectric bimorph beam, we experimentally found that the direct feedthrough term, which should have a positive value in the conventional model, has a negative value. This paper proposes a model in which the direct term is negative, considering the electrical coupling caused by the structure of a piezoelectric bimorph beam. In addition, the stability of the control system is shown based on the negative imaginariness, and the IRC is shown to be applicable to a control object with a negative direct feedthrough term.

The packaging of agricultural products is of paramount importance for managing the food supply with innovative and safe products. The consumer, at the same time, is increasingly aware of the impact of packaging on the environment ensuring that the value of packaged agri-food products depends on the threefold control, quality, protection. The present study reveals new possibilities that cover (a) food safety and traceability by applying smart packaging solutions, and (b) ensuring and verifying the authenticity of packaged agri-food products. The innovative sensors and procedures which are being developed enable novel intelligent traceability systems aiming to provide product quality and safety information to effectively control the supply chain and predict the remaining shelf-life of the product. To this end, low-cost, batteryless wireless interdigital sensing systems equipped with two-way response antenna, have been directly deposited on packages made of any material or shape, having the possibility of integrating in real-time with packaged agri-food products. Also, new methodologies are being developed, aiming to verify food authenticity leading to the protection of the consumer from fraud, counterfeiting or improper packaging of protected designation of origin products such as dairy products, olive oil, as well as herbs and spices.

This preliminary study presents a sound wave visualization method using mechanoluminescent composite diaphragms made of mechanoluminescence particles (SAO). To visualize the acoustic wave, the concept of Cymatics is used to make the sound waves and vibrations observable (the human sense of vision), as it is the most discriminating human sense. The goal of this study is eventually to extract the frequency information from images captured by compact image sensors without fast Fourier transform (FFT) whereas most previous studies on sound visualization focus on a technique used to enhance the understanding of acoustical behaviors, such as reflection, diffraction, and interference. In this study, highly pressure-sensitive mechanoluminescent diaphragms will be fabricated and used to produce the images in response to audible sound excitation such as speech. This initial study will offer the potential application for new means of speech recognition principle because a systematic visual perception of the isolated speech words can be achieved using the proposed sound visualization method.

Cellulose nanofibers (CNFs) have attracted attention in a diverse area of applications due to their amazing mechanical properties and lightweight. Recent advances in enhancing the mechanical performance of nanocellulose filaments and films have reported efforts to align the individual cellulose nanofibers using different methods. Among them, the most recent being the use of electrical fields experimentally. It is important to investigate at the molecular level if the application of low electric fields on CNF can induce alignment and what effects these electric fields have on the molecular structure of the CNF. This study reports a molecular dynamics (MD) study of CNF model in a varying electric field (EF) strengths and direction. The MD simulations were conducted in GROningen Machine for Chemical Simulations (GROMACS) and the All-Atom Optimized Potential for Liquid Simulations (OPLS-AA) force field was used. Induced electric field alignment was investigated in terms of how quickly the alignment begins, how long it takes for complete alignment, and the ability to maintain any achieved alignment at different electric fields. To understand the electric field-induced structural changes, the hydrogen bonding network, hydrogen bond length, radius of gyration, and deviation from the original model are critically analyzed. The results show that CNF can be successfully aligned in low electric fields without compromising its molecular structure.

Polycaprolactone (PCL) is a semicrystalline thermoplastic polymer well-known as a nontoxic and biodegradable material. Due to this nature, PCL has been studied for drug delivery and a bioscaffold in tissue engineering. However, it has incomplete properties as the structural materials such as relatively low mechanical properties, low surface energy, and long degradation rates. Thus, this study aims to complement the previous shortcomings and present the possibility of a more advanced biomaterial by forming nanocomposites with cellulose nanocrystal (CNC), one of the abundant natural polymers with high specific modulus and strength, environmentally-friendliness, and nontoxic. Bulk materials with various concentrations of CNC in PCL matrix were fabricated, and a three-point bending test was conducted. The measured bending modulus was compared with the estimated values based on the rule of mixtures of the nanocomposite and surface morphology was investigated by scanning electron microscopy.

Carbon neutrality is now important and inevitable in the 21st century for climate change and global warming, and numerous industries are trying to decrease the emission of greenhouse gases. Also, numerous studies have been followed in the steel industry, and FINEX was first devised and is now used as decreasing 20 % of greenhouse gases during the production of iron. Furthermore, the HyREX that is the production process of direct reduced iron with hydrogen was devised for carbon neutrality by replacing coal with hydrogen. In this study, HyREX was studied for its temperature and the number of cycles with 7 % of hydrogen by simulation using Chemical equilibrium with applications to find optimized conditions since it is challenging to research as an experimental approach due to the problem of cost and size. The optimized condition was defined as the point that reduces all oxygen from iron ore because the rest of iron ore or oxides can cause the problem of purity. The temperature range was set between 800 K to 1200 K as known temperature for the production of direct reduced iron that is below the melting point of iron. The amount of provision of iron was constant as 100 g and the percentage of hydrogen was based on the weight. As a result, 69.942 g of direct reduced iron was produced with 100 g of iron under 1200 K of temperature and 5 cycles with 7 % of hydrogen.