This PDF file contains the front matter associated with SPIE Proceedings Volume 11378 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Force feedback in minimally invasive surgeries is important in preventing iatrogenic injuries under remote controlled robotic surgical platforms. In this study, an ultra-thin biocompatible pressure sensor is designed to be installed onto three precurved overlapping 1 to 2.5 mm-diameter nitinol concentric tube manipulators of a miniaturized neurosurgical robotic tool to provide low-pressure range force feedback for pediatric surgeons. The finalized design can detect force magnitude and location with excellent signal-force proportionality from under 10 mN to 1 N, while adapting with the bending motions of the precurved tubes. The low-pressure range force feedback system in this study ensures safety and quality for very small neurosurgical tool used in pediatric minimally invasive operations.

Visual impairment constitutes a compelling issue for our society. The aging of our population will cause a rise in the number of individuals affected by these debilitating conditions, which often challenge people in their daily routine and bear significant healthcare costs and consequences on society at large. Technological progress offers unique means to improve life conditions for the visually impaired, who still rely on low-tech systems, such as canes and service dogs. Here, we present a novel design for a piezoelectric belt integrated into a backpack, which can provide vibrotactile stimulation to the abdomen to signal the presence of obstacles. The belt is composed of an array of ten macro-fiber composite (MFC) actuators, arranged in a matrix of five columns by two rows. Obstacle identification and localization is afforded by a computer vision system, developed by our collaborators. The output from the array of actuators is controlled by the computer vision system, such that, if an obstacle is identified in a certain “capture field”, the corresponding actuator in an egocentric and spatiotopically preserved fashion is activated. The actuators comprise an encapsulated aluminum-backed MFC, driven by a tunable astable multivibrator. The resonance frequency of the actuators is tailored by adding a variable mass to a hollow cylinder fashioned as a protusion secured to the tactor, transmitting vibrations from the MFC to the skin of the human-in-the-loop. This new design allows us to enhance the peak-to-peak displacement of actuators of more than a tenfold factor over the 10-200 Hz frequency range, thereby surpassing, with a robust margin, the 50 μm threshold necessary for reliable discrimination given abdominal somatosensation.

Here, we demonstrate a process of developing strong and flexible CNT/Cotton conductive yarns. Highly spinnable millimeter tall CNT arrays produced by catalytic chemical vapor deposition were drawn into yarns and simultaneously wrapped over cotton yarn. The diameter and resistance of the CNT/Cotton yarn can be tuned for different applications and the lowest resistance obtained was 3.92 ohm/cm. The CNT/Cotton yarns were evaluated and compared in terms of tensile behavior and electrical conductivity. Integrating CNTs by wrapping over cotton yarn showed around 30% improvement in mechanical properties. This is further enhanced by the application of a polyurethane binder and prevents the delamination of CNTs from the yarns during mechanical strain. Scanning electron microscopic (SEM) images show uniform wrapping of the CNTs. The produced yarn can withstand 1000 loading cycles with a very small decrease in conductivity. The yarn was used to demonstrate powering a LED. The CNT/Cotton sheath-core yarn was also directly supplied to a whole garment industrial knitting machine to form a three-dimensional textile. The knitted structures showed very stable strain sensing properties and can accurately track the movement of a finger. When voltage is applied, the knitted smart textiles shows rapid heat generation and uniform distribution of heat. It was found that at 3V the knitted structure produced a temperature higher than body core temperature within 15 seconds. The developed yarn has the potential for the production of smart textiles on an industrial scale.

A continuous fabrication process for high-strength nanocellulose based long-fiber (NLF) has been researched as a key process to fabricate natural fiber-reinforced polymer composites with high specific modulus and strength. The process was custom-designed by utilizing the wet spinning and stretching methods with dry process. First, nanocellulose was isolated from wood pulp by using a combination of chemical and physical methods. Apparatus for the process was self-produced and the process parameters such as the speed, position, number of wheels were experimentally investigated. Among the various designs, two specific setups were chosen and the speed of the wheels was optimized. The success of the process was determined by the sustainability of the setups for more than 30 min. The results were evaluated by using the tensile test and scanning electron microscope.

Carbon nanotube (CNT) wires are mechanically stronger and extremely lightweight nanomaterials with highly efficient mechanical, thermal and electrical properties compared to the conventional materials. The new applications of these superior nanomaterials include aircraft, energy, biomedical, sensor, defense, electronics and space. One very interesting potential application of carbon nanotubes is in electrical wiring. Conventional electrical wires made of copper and aluminum suffer from several problems including weight (an issue in aerospace applications), skin effect (hindering their use in modern telecommunications), mechanical performance (critical in overhead power lines and ductility), and electromigration (severely damaging microscopic wires in electronics applications). Moreover, the growing demand for these conventional metal conductors and the continually increasing prices suggests that a low-cost material that can outperform conventional conductors would be highly desirable. Hence, carbon nanotubes are the material of great interest for those. In the study, CNT wires were immersed into the acid bath under ambient conditions for different time periods to analyze their physical property changes. Chemical treatment drastically changed the physical dimensions of the CNT wire, including increase in diameter and a decrease in length. Also, chemical bonds were created between the CNTs, which might increase the properties of the CNT wires. Under tensile load, chemical treatment has been proven to slightly increase the tensile strength and conductivity of the CNT wires, but the test results were scattered substantially. This study may create new possibilities to enhance the physical and chemical properties of CNT wires in a number of different industrial applications.

Damage and mechanical failure are detrimental for materials in engineering applications. However, recent studies have shown that properly designed debonding and pullout phenomena in composite fractures can be implemented to introduce added functionalities by damage induced surface texturing (DIST). In the DIST approach, randomly oriented or aligned fibers are incorporated in a polymeric matrix, followed by transversal shearing of the surface. As a result, the shear-fractured surface will have protruded fibers on it because of debonding followed by subsequent pullout. The protruded fibers play a key role in imparting new functionalities to the cut surface. One of the drawbacks of DIST is that the introduced surface functionalities (i.e. hydrophobicity) are affected by mechanical weathering since the commercial carbon fibers used lack abrasion and flexural fatigue resistance. In order to overcome this issue, carbon nanofibers (CNFs) can be used resulting in enhancing the surface wettability of generated surfaces from hydrophobic to the superhydrophobic regime. We have shown that by using 36 wt.% chemical vapor grown hollow carbon nanofibers in styrene-ethylene/butylene-styrene (SEBS) matrices the water sessile-drop contact angle of pristine cut SEBS samples increases by 41% from 106.1˚ ± 2.9˚ to 151.7˚ ± 1.7˚. Although the CNFs are small in diameter size (100 nm) with respect to CFs having two orders of magnitude larger diameters, they provide a high specific surface area of up to ~ 50 m2/g while the latter has a specific area of ~ 1 m2/g. The higher surface area generated by protruded CNFs on the surface can introduce air pockets between the surface and water droplets necessary for surface supperwettability. DIST is a simple, economical, and scalable. In addition, there is no need to use costly and time-consuming post-processing stages to introduce anisotropic properties into the material.

Graphene is a two-dimensional material and has demonstrated an exceptional electronic and photonic properties for unlimited applications including its use in extreme environments of the space. There are several known techniques of formation of graphene onto different types of substrates such as the substrate transfer process and direct deposition. In this work, we deposited monolayer graphene over copper and nickel substrates in NanoCVD-8G Graphene reactor using argon plasma, and methane as a carbon source and studied effects of gamma irradiation using Cobalt-60 source. Radiation effects on crystalline structure of graphene is examined using Raman Spectroscopy and X-ray Photo Electron Spectroscopy (XPS). In our experiment, we used irradiation dose from 1 kGy to 2.65 kGy for different samples of graphene over copper and nickel substrates. For the graphene grown on the nickel substrates, we exposed the irradiation dose of 1.0 kGy and 2.5 kGy on two samples, respectively. For the graphene grown on the copper substrates, we exposed 1.25 kGy, 1.75 kGy, and 2.65 kGy irradiation dose on three samples, respectively. We observed D-peak in graphene deposited over nickel and copper substrates caused by disordered structure of graphene after Co-60 exposure. After the Raman spectroscopy and XPS studies, same amount of irradiation was used for second set of irradiation dose experiment. XPS data on Co-60 exposed samples showed four peaks positioned at 284.8eV, 285.3eV, 286.0 eV and 288.5 eV for C-C, C-OH, C-O-C and COOH bonds, respectively. Analysis of the results shows weakening of C-C bonds and formation of C-OH, C-O-C and COOH bonds implying reduced electrical conductivity of graphene.

In this contribution, we report on the development of transparent and soft vibrotactile actuator array that can be utilized in the next-generation touch display panels. Explicitly, we believe that the actuator array can more efficiently be employed in rollable smart windows of a smart vehicle. The proposed actuator array mainly composed of dielectric elastomer layer and ionic conductors. In order to construct the proposed vibrotactile actuator array, the dielectric elastomer is sandwiched between two soft ionic hydrogels. The ionic hydrogels contract each other under the applied electric field because of electrostatic attraction. As a result, the dielectric elastomer is compressed in its thickness direction and expanded to the out-of-plane direction. When the applied electric field is removed, the dielectric elastomer and ionic conductors are recovered to its initial state by elastic restoring force. When the alternating electric signal is applied to this structure, it generates vibration. To construct 4 × 4 vibrotactile actuator array, four perpendicular stripes and four longitudinal stripes made of ionic conductors were put on/under the planar dielectric elastomer. The proposed actuator array generates the vibration in wide frequency range and strong vibration of about 0.8 g (g = 9.8 m/s2) at a resonant frequency was noticed. We demonstrated and confirmed that the vibration acceleration of each cell unit can be controlled by the input voltage (0.1 kV to 3.5 kV) and can be operated individually. The data indicate that the proposed vibrotactile actuator array could have utility in center fascia, deformable or transparent devices.

The metabolic activity of microorganisms is considered one of the reasons why evaporators of the automobile and household air conditioning systems produce the malodor. The odor-causing by microorganisms can be reduced by incorporating biocide in the hydrophilic coating. The objective of this work was to understand the mechanisms how the microorganisms produced the odor and to analyze the chemical compound of the odor. Experiments were conducted to measure the variation of odor and to assess the antimicrobial property of epoxy resin-based hydrophilic coatings of evaporators. Then the microorganisms used the experiments were as followed; four bacteria cultured from an evaporator of household air conditioning system were metylobacterium phylloshaerae, metylobacterium radiotolerans, sphingomonas aquatilis, and bacillus subtilis, and three molds were aspergillus niger (ATCC 6275), paecilomyces variotii (ATCC 18502), and trichoderma viren (ATCC 9645). Then the four bacteria and three fungi mixed with similar concentration respectively and were recoverable repeatedly for seven days. The change of intensity and types of odor-causing chemicals as a result of their metabolic activity were measured by Gas chromatography-mass spectrometry (GC-MS) measuring and sensory evaluation of odor. In order to compare the number of microorganisms, the samples were incubated for two days at 35°C and R2A agar was employed for the isolation of bacteria and fungi.

Chemical warfare agents (CWAs) are extremely lethal spices of mass destruction even at the low dosages which gives crucial importance to early detection and prevention. As a simulant of nerve agent sarin, Dimethyl methylphosphonate (DMMP) can be used because it has non-toxic properties and mimics the structural composition of sarin. In this paper, we summarize the CAW detection by designing a surface acoustic wave (SAW) and fabrication of polyhedral oligomeric silsesquioxane (POSS), thiourea (TU) and other hybrid composite materials for sensing materials. The sensing hybrid materials were fabricated by hydrosilylation reaction process and hydrothermal and thermal reduction process respectively. The synthesized materials were spin-coated or drop coated on the SAW and quartz crystal microbalance sensor as a thin layer deposition on the surface. Based on our experiments, several sensing polymers and hybrid oxides will be suggested for potential candidates of CWA sensing layers on portable SAW device.

Nanocellulose has a great potential as a renewable material due to its high mechanical strength, high Young’s modulus, low density and eco-friendliness. Once a bulk material is made with it, then the bulk material made with nanocellulose can be a renewable bulk material, which is eco-friendly, lightweight and strong. This paper aims at testing the feasibility bulk material processing by using nanocellulose, specifically cellulose nanocrystal (CNC). The fabrication is carried out through steam with high temperature and high pressure to form hydrogen bonds between CNCs, followed by heat and pressure molding. Crystalline structures of the prepared bulk materials are investigated by using X-ray diffraction and morphology and mechanical properties are investigated by using scanning electron microscope and dynamic mechanical analysis. Also, machining behavior for the nanocellulose bulk material is tested by using end mill to see its manufacturing possibility. In addition, the surface roughness is measured by using optical surface profiler with endmill machining part. Machining heat generation is investigated by thermal imaging camera between endmill tool and machined surface of the sample.

This study presents the piezoelectric property test of ultrathin cellulose nanofiber (CNF) film and calculate the piezoelectric coefficient by using piezoresponse force microscopy (PFM). Cellulose is known to have piezoelectric properties. However, its measurement is not easy. The mechanism of PFM is based on detecting the piezoresponse induced by the inverse piezoelectric effect from target sample. We applied the PFM to characterize the piezoelectric properties of ultrathin CNF film which is fabricated by microfabrication method under clean room condition. For characterizing the piezoelectric properties of ultrathin CNF film, the PFM standard sample periodically poled lithium niobite (PPLN) sample was utilized as reference sample. By applying AC voltages through conductive AFM probe to ultrathin CNF film surface, the amplitude data of ultrathin CNF film is recorded and used to calculate the piezoelectric coefficient. Corona poling, electrical in-plane alignment and high magnetic field alignment methods are introduced to align the ultrathin CNF film. According to the different alignment methods, the aligned ultrathin CNF films show different piezoelectric behavior.

Image sensing technology has a great impact on our daily life as well as the entire society, such as health, safety and security, communication systems, and entertainment. The conventional optical color sensors consist of side by side arranged optical filters for three basic colors (blue, green, and red). Hence, the efficiency of such optical color sensors is limited by only 33%. In this study, a vertically stacked color sensor is investigated with perovskite alloys, which has the potential to provide the efficiency approaching 100%. The proposed optical sensor will not be limited by color Moire error or color aliasing. Perovskite materials with suitable bandgaps are determined by applying the energy shifting model and the optical constants are used for further investigations. Quantum efficiencies and spectral responsivities of the described color sensors are investigated by three-dimensional electromagnetic simulations. Investigated spectral sensitivities are further analyzed for the

The wireless communications, especially cellphones have popularly been used. The frequency of cellphone communication has been shifted 900 MHz to 5.68 GHz including 2.45 GHz which is water resonance frequency in earlier stage. The effects of this microwave on humans have also issued based on current researches. In addition, the new rule adopted today creates a new Upper Microwave Flexible Use services in the 28, 37, and 39 GHz bands, and a new unlicensed band at 64 -71 GHz. The research reported herein, seeks to review possible effects of microwave signals with the frequencies ranging from 900 MHz to 100 GHz on the humans and environment. In this paper, the dielectric properties of various human tissues, especially human brain is used for estimation of influence within the frequency ranges.

This talk discusses analytical simplification of a multi-physics model for ionic polymer-metal composite (IPMC) sensors. Some methods including finite element method, and assumed mode method based on separation of variables are introduced. For the finite-element or the assumed-mode simulation, we have built in-house MATLAB programs. The obtained approximated models are represented by ordinary differential equations, and the computational cost is greatly reduced by the proposed simplifications. The magnitudes of the error in the approximated models for open-circuit voltage are kept acceptable level within at most 2%, although the computational time is greatly reduced to 1/100 to 1/1000.

The modeling in this study was conducted to maximize the high performance of adhesive materials. Aluminum nitride (AlN) and epoxy resin were used to model AlN in the form of a sphere and resin in a liquid state. The results are expected to be dependent on the location of the sphere in the resin. First of all, spherical AlN is regularly stacked in the basic form of 3x3. Secondly, the volume ratio of AlN was maximized at a unit volume considered of the packing factor of AlN. Air pockets with the same diameter of AIN can be substantially added inside the resin. Then, the heat transfer coefficient of the air was very low, so it was considered as a factor that could sufficiently affect the heat transfer coefficient of the adhesive material. The modeling was compared the cases with and without the air pockets. Thirdly, the modeling of the same structures showed the larger heat transfer rate when the material was changed to zinc oxide (ZnO), which has the larger heat transfer coefficient than AlN. Finally, the molecular crystal of ZnO can be implemented as a tetrapod type. The ZnO of tetrapod type had the good heat transfer rate because of the greater proportion per unit volume than the sphere.

We present experimental verification of tree-dimensional (3D) 1x4 Y-branch splitter based on IP-Dip polymer as a core and polydimethylsiloxane (PDMS) Sylgard 184 as a cladding. The splitter was designed to operate in a wavelength region around 1550 nm. The design parameters of the splitter were optimized according to required optical properties and technological limitations. Based on the simulation results, the 3D Y-branch splitter was realized using direct laser writing lithography. Cladding of the splitter was prepared by PDMS pouring and curing. The measurements were performed by coupling optical signal into the splitter using standard SM fiber. By intensity monitoring of CCD camera we successfully documented splitting of the input optical signal into four output signals.

This paper proposes a laser sensor-based robotic smart method and introduces the workflow of the method and the key technologies involved, such as point laser locating technology, line laser hand-eye calibration technology. The software framework required for the method of operation is described. The techniques described in this article can avoid the difficulty of robotic manual teaching and improve the smart level of robotic operations and product quality.

To transition from stationary ECG monitors to portable ones, traditional Ag/AgCl wet electrodes must be replaced with more robust and flexible sensors that can be integrated into wearable textiles for long-term monitoring. Flexible polymer composites embedded with carbon nanotubes (CNTs) are an ideal candidate for this application due to their low reactivity and desirable mechanical properties. However, these composites may need to be incorporated directly into textiles and clothing, which often have mechanical properties that vary greatly from the polymeric electrode. Here, we study the mechanical and electrical properties of three different polymers, polyvinylidene difluoride (PVDF), thermoplastic polyurethane (TPU), and styrene-butadine-styrene (SBS) under varying loading of CNTs when integrated into clothing as an ECG electrode.

This paper presents the preliminary study on monitoring of intraocular pressure (IOP) of human eye by using optical coherence tomography (OCT). Because hypertension IOP can lead to Glaucoma, one of chronic diseases of the optic nerve, the periodic monitoring of IOP through tonometry is essential to prevent the Glaucoma. One of the most common tonometry methods to estimate IOP includes measuring corneal deflection by using either a direct contact or non-contact (e.g. air puff) impact force. However, this approach may be harmful to human eye. Therefore, it is necessary to develop the more reliable and safe monitoring method. In ophthalmology, the differentiation of open-angle glaucoma and normal eyes is used to monitor the IOP by using. Typically, peripapillary vessel density or superficial perifoveal macular vessel density measurements are currently utilized. In this study, optical OCT images of bovine eye was captured with different IOPs of bovine and analyzed to extract the signature where defines the relationship between IOP and optical OCT images.

Output-only based damage assessment of delaminated smart composite structures is increasingly appealing due to its easy availability in real engineering applications. In this work, structural vibration responses of the pristine and delaminated composite structures are processed via Fast Fourier Transform (FFT) and Convolutional Neural Network (CNN) for the classification of healthy and various damaged cases. The dynamic model for the healthy and delaminated smart composite laminates is developed by incorporating of improved layerwise theory, higher-order electric potential field, and finite element method. Structural vibration responses are obtained through a surface bonded piezoelectric sensor by solving the electromechanically coupled dynamic model in the time domain. FFT is used to construct vibration-based images from the transient responses of the sensor and CCN is used to classify those images into healthy and damaged classes. The confusion matrix of CNN showed physically consistent results and an overall classification accuracy of 90% was obtained. The pre-trained CNN was also tested to predict labels for new cases of delaminations in the smart composite laminates. The essence of the proposed method is that it requires only low-frequency structural vibration responses for the detection and localization of delamination in smart composite laminates.

Construction of graphene-based nanosensor is presented for the detection of viruses and bacteria as infectious agents. Viruses and bacteria are cause of different form of diseases. Detection mechanism for classification and identification of biological agents as well as viruses are paramount at early stages of illness. Fabrication of graphene nanosensor based on surface plasmon resonance (SPR) technique and field-effect for viruses, bacteria, proteins, and nucleic acids detection is proposed in this article.