bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Electrical Impedance Tomography Drive Pattern for Fast and Accurate Gesture Recognition With Less Electrodes
Authors: Ma Gang , Hao Zhiliang , Wu Xuan , Wang Xiaojie 
Published: December 2019

Abstract
This paper presents an optimal Electrical Impedance Tomography (EIT) drive pattern for real-time gesture recognition, which can reduce the measurement time and realize a performance trade-off between the accuracy and the time response. This method is achieved by feature selection and model explanation. We designed eleven hand gestures to verify the proposed approach. Compared to the 8-electrode method, the optimal electrode drive pattern achieved a recognition accuracy of 97.5% with seven electrodes and the measurement time was reduced by 60%. To illustrate the universality of this method, we performed a contact detection experiment. By setting seven labels on the conductive panel and using optimal electrode drive pattern, the detection accuracy reached 100% with seven electrodes and the measurement time was reduced by 85%.
Design and Testing of a Wall-Climbing Robot With Under-Actuated Force Adjusting Mechanism
Authors: Wu Xuan , Liu Hong , Wang Xiaojie 
Published: December 2019

Abstract
The paper introduces the design and testing of a tank-like modular wall-climbing robot (WCR). Firstly, a bioinspired dry adhesive patterned with papilla-like array is fabricated, and its quasi-static adhesive properties is tested and evaluated. Based on the material’s properties, a single tank-like module using timing adhesive belts is optimally designed for maximum adhesive force. An under-actuated four-bar compliant linkage is utilized to connect the two modules of the WCR. The lengths of the linkage are optimized in keeping both of the modules having constant preloading forces on surfaces with different inclinations. Experimental results show that the compliant link functions like the digital joint of the gecko that is able to maintain enough preloading force for each module on the surfaces of variable inclinations, making the robot adapted to surface transitioning easily.
Transient Fluid-Structure Interaction Analysis of a Solid State Ornithopter Wing
Authors: Katibeh Mohammad , Bilgen Onur 
Published: December 2019

Abstract
One of the means of flight is via flapping and there were many attempts to mimic the wing motion of a bird for centuries. One interesting concept for achieving flight via flapping is the so-called solid-state ornithopter concept which works by using induced strain actuators such as piezoelectric materials for flapping. In this research, we seek to gain a better understanding of the feasibility and performance of the solid-state ornithopter concept. In this paper, the purpose is to analyze a solid state ornithopter wing concept and to study the effect of different geometric parameters. A two-way fluid-structure interaction analysis method is utilized since the geometry of the wing is changing throughout the flapping cycle, and the fluid and the solid domains interact significantly. A parameterized model is utilized in both solid and fluid domains, and the two domains are coupled. Different geometric parameters are defined in the model so that the system-level performance metrics as a function of each parameter can be examined.
A Bioinspired Piezocomposite Peristaltic Pump: An Electromechanical Euler-Bernoulli Beam Model and Parametric Analysis
Authors: Shan Xin , Bilgen Onur 
Published: December 2019

Abstract
This paper investigates the optimal geometric parameters for a bioinspired peristaltic piezocomposite pump with the use of an electromechanical Euler-Bernoulli beam model. The peristaltic pump is a self-contained propulsion system involving a series of piezo-active soft cymbal-like segments that are connected with passive soft connective segments. A series of phased excitations in expansion and contraction applied to different active segments of the channel create a traveling wave along the axis of the channel, which in return “propels” the fluid in one direction. A parametric analysis, based on the Euler-Bernoulli beam model, is conducted to improve the effectiveness of the cymbal-like piezocomposite actuators. Area change of the cymbal-like actuators, which is correlated to the propulsion power, is studied based on the analysis of the moment, curvature, and area change due to excitation. Area change is also used to evaluate the effectiveness, and to decide the optimal geometric parameters of the piezocomposite actuators.
Self-Sensing for Twisted String Actuators Using Conductive Supercoiled Polymers
Authors: Bombara David , Mansurov Vasilii , Konda Revanth , Fowzer Steven , Zhang Jun 
Published: December 2019

Abstract
The twisted string actuator (TSA), as a recently discovered artificial muscle, has attracted a lot of attention as a compliant and powerful actuation mechanism. A TSA consists of two strings attached to a motor on one end and a load on the other end. The motor’s rotation twists the strings and generates linear actuation. A common challenge is to obtain TSAs’ strains using compact approaches. Previous studies exclusively utilized external position sensors that not only increased system cost, size and complexity, but also lowered actuator compliance. In this paper, self-sensing strategies are presented to estimate TSAs’ strains without external sensors. By incorporating conductive and stretchable nylon strings, called super-coiled polymer (SCP) strings, into TSAs, their strains can be estimated from the resistance values of SCP strings. Two self-sensing configurations are realized: (1) TSA with one regular string and one SCP string, and (2) TSA with two SCP strings. Experiments are conducted to show the correlation between the length and resistance of TSA under different conditions. Polynomial and Preisach hysteresis models were successfully employed to capture the Length – Resistance correlation and to estimate TSA’s length using the resistance.
Evaluating Fretting Wear on 3D-Printed α-, β-, γ- Additives Hybridized NiTi Shape Memory Alloy
Authors: Bodunde O. P. , Gao S. M. , Qin M. , Liao W. H. 
Published: December 2019

Abstract
Nickel-Titanium (NiTi) shape memory alloys (SMAs) are a class of promising materials for bio-implant, transportation, and aerospace applications. These interesting applications of SMA are as a result of their ability to exhibit shape memory effect (SME) and super-elasticity (SE). SMAs, especially NiTi which has been proven to have good mechanical properties, are however limited by their operational fatigue as reported in the literature. In this paper, a near equiatomic NiTi SMA was hybridized with zirconium (Zr), molybdenum (Mo) and copper (Cu), which are available and economic viable α-, β-, γ- stabilizing additives suitable for NiTi SMAs. Each of Zr, Mo, Cu were hybridized separately with the bare near equiatomic NiTi SMA. The compositional requirements for each of the sub-hybrids (NiTi-α, NiTi-β, and NiTi-γ respectively) were experimentally determined to know the optimum composition which could indicate the presence of austenitic and martensitic phases. Scan electron microscopy (SEM) was performed on each of the hybridizing additives as well as the bare equiatomic NiTi to determine their particle sizes and investigate their compatibility (between 30 and 40 microns) with the 3D printer used in the study. X-ray diffractometric (XRD) analysis also was carried out on the bare SMA and its additives to determine the presence of B2 and B19’ peaks. Afterward, NiTi-α, NiTi-β, and NiTi-γ were 3D printed to produce fretting wear test specimens and finally, the fretting wear behaviors of the NiTi hybrids were studied in detail with the objective of testing their performances under fretting wear mode as it may be required for an application. A tungsten carbide counter-body was used. The results from the characterization through XRD indicated that all of α-, β-, γ- stabilizing additives with NiTi respectively showed the presence of B2 and B19’ in the inter-metallic phases. Details of wear microstructure were reported and its information could be useful for professionals who require hybridized NiTi alloys for various engineering applications.
Energy Harvesting From the Vibration and Rotation of Host Systems Using Piezoelectric Devices
Authors: Cooley Christopher G. 
Published: December 2019

Abstract
This work analyzes the energy harvested by a piezoelectric vibration energy harvester that is attached to a rotating host system, like an automotive tire, that has superposed translational vibration. The device experiences once-per-revolution dynamic excitation from rotation and, because the host system translates, additional speed-dependent excitation from input vibration. The device consists of a piezoelectric beam with a proof mass that displaces tangentially in operation so that large, troublesome centripetal accelerations can be avoided. The dynamic response and power harvested are determined in closed-form. The speed-dependent properties of the response components are determined. With excitation from rotation and vibration, the device harvests substantially more power than if the system were excited by either rotation or vibration alone. Numerical results are shown for an example device over a wide range of rotation speeds. The device can harvest 185 mW of power at its maximum when the rotation speed is near 1,000 rpm. The device provides more than 30 mW of power for speeds between 817 rpm and 1,195 rpm. Harvesting energy from vibration naturally leads to wider speed bandwidths where large amounts of power are available.
Pneumatic Artificial Muscle Development and Manufacturing Process and Verification Testing for Space Flight Application
Authors: Netwall Christopher J. , Thomas James P. , Kubista Michael S. , Griffith Kerry A. , Kindle Christopher , Schlater Jordan , Hays Joseph T. , Feerst Phillip A. , Wereley Norman 
Published: December 2019

Abstract
The U.S. Naval Research Laboratory (NRL) has been developing a space-rated 7 degree of freedom (DOF) robot arm with a high payload-to-mass ratio as an alternative design to motor-gear driven robotic manipulators. The robot arm employs antagonistic pairs of pneumatic artificial muscle (PAM) actuators to control each degree-of-freedom (DOF) to achieve large force outputs relative to the PAM component masses. A novel feature of the NRL PAM actuator was the integration of the pneumatic control components inside the pressure-bladder, which not only reduces the volume of the robotic arm hardware but also reduces the pressurized-gas actuation volume in the PAM enabling significant reductions in gas consumption during actuation. This multifunctional design enables reductions in launch-weight costs and increases in operational endurance for space applications. The integration of these PAMs into a well-designed robotic-arm structure, in tandem with a newly developed control algorithm, has the potential to exceed the performance metrics of traditional motor-driven robot arms. This paper describes the development of the improved efficiency PAM design that is advancing this technology towards space flight readiness.
3D Printed Segmented Flexible Pneumatic Actuator
Authors: Gonzalez David , Garcia Jose , Newell Brittany 
Published: December 2019

Abstract
Soft actuators have been studied and analyzed as a new solution for soft robotic technologies. These types of actuators have many advantages due to their predictable deformations and their ease of control, enabling them to hold and move delicate objects performing complex movements in confined spaces. Soft actuators can be made using different manufacturing processes, but the most common is mold casting. However, this manufacturing process involves several steps, increasing the manufacturing time and hindering changes in the design. This paper presents a novel design of a 3D printed soft pneumatic actuator based on additive manufacturing, achieving design versatility and performance. The produced actuator has seven that can be individually controlled. The actuators were made using fused deposition modeling (FDM) technology in one continuous process and without support material. The mechanical performance of the soft actuators was demonstrated, analyzing the deformation in the z-axis based on input pressure.
Preliminary Experimental Investigation of Control Parameters for the Electroresistive Heating of SMA Knitted Textiles
Authors: Marbaker Rachel , Utter Brent , Eschen Kevin , Abel Julianna 
Published: December 2019

Abstract
Knitted textiles manufactured from shape memory alloy (SMA) monofilaments possess advanced capabilities for distributed and complex actuation and are suited for a range of emerging needs in aerospace, biomedical, and robotics applications. In general, high currents for short periods of time provide sufficient electroresistive (Joule) heat to cause SMA wires to transform to austenite. However, SMA knitted textiles are difficult to electroresistively heat because the interlocking knit structure short-circuits the flow of current, causing localized overheating and isolating the transformation of the material along the current path. One approach for heating SMA knitted textiles is to drive pulses of high current between pairs of electrodes positioned across horizontal courses (rows) of knitted loops. This research presents a preliminary experimental investigation of the effects of factors related to electroresistive heating for SMA knitted textiles. A design of experiments analysis with two levels of four factors was conducted using a 24–1 fractional factorial design. The factors included the voltage of the power supply connected to the current amplifiers; a geometric factor defining the horizontal spacing of the electrodes attached to the knit sample; and two waveform factors: On Cycles and Off/On Cycles, which defined the length of time each current amplifier was enabled and disabled. Actuation performance was quantified by the actuation displacement and actuation force of the knit sample. Preliminary results suggest that voltage is the most influential factor, but also indicate that interactions between the geometric and waveform factors have significant effects on the heating and actuation performance. The characterization of these factor interactions has the potential to inform optimal electroresistive heating approaches for SMA knitted textiles, enabling integration into applications such as wearable technologies where convective heating is not practical.
Woven Nitinol Fabric Strips Characterized in Tension via Finite Element Analysis and Geometric Modeling
Authors: Skalitzky Amanda , Petersen Caleb , Gurley Austin , Beale David 
Published: December 2019

Abstract
Nitinol in the form of wires, tubes, and plates have been explored extensively; however, the characteristics of Nitinol as a woven fabric have so far been little-studied analytically. It would be easier to design such a fabric if conventional fabric models were known to apply to Nitinol fabrics, potentially with modifications required by Nitinol’s unique properties. A 25 mm wide Nitinol narrow fabric has been manufactured using traditional weaving equipment using a proprietary process that achieves a uniform and tight weave. Heat-treatment and straight shape-set is applied to a single Nitinol wire and the woven Nitinol fabric at 600°C for 30 minutes. The 0.25 mm Nitinol wire constituent was tested using differential scanning calorimetry (DSC) to determine the transition temperatures (Mf, Ms, As, and Af), which were found on average to be 54.5°C, 66.9°C, 88.7°C, and 103.5°C respectively. Both the Nitinol wire and fabric were tested in a temperature-controlled chamber (testing temperatures ranged from room temperature to 200°C) in which the tensile stress-strain characteristics were observed. It was determined that existing analytical models can be employed to accurately estimate the overall tensile stiffness of woven Nitinol fabrics in a small-strain regime. Additionally, it was confirmed that the tensile loading of woven Nitinol fabric can be modeled in MSC.Adams with beam elements. In combination with the geometric model presented, woven Nitinol fabric behavior can be predicted from the experimental behavior of the constituent Nitinol wire.
Smart Material Actuation of Multi-Locomotion Robot
Authors: Jovanova Jovana , Domazetovska Simona , Changoski Vasko 
Published: December 2019

Abstract
The focus of this research is modeling, simulation and prototyping of multi-locomotion bio-inspired robot. The actuation is based on shape memory alloys (SMAs) smart materials to achieve different styles of movements. Soft-bodied robots have potential to exploit morphological computation to adapt and interact with reduced control complexity. Observing the movement of a caterpillar that could produce different locomotion such as crawling and rolling, our team designed and developed a bio-inspired robot.
Analytical models of the different bio-inspired movements are derived and analyzed in Matlab in this work. The models rely on segmented approach actuated by smart materials in order to achieve the desired position. Smart material actuators are a promising but challenging actuation mechanism because of their design, large deformation possibilities, external stimuli shape change and high power density. The body parts are from a soft silicon elastomer. Between the silicone body parts, SMA spring are embedded, used as actuation force. Between the two segments, SMA spring as actuators are generation strain to bend the body and achieve crawling and lifting.
This work is initial modeling for multi locomotion of soft bio-inspired robot and will be followed by a detailed analytical and numerical modeling and simulation, finalizing with a functional prototype.
Experimental Technique to Estimate Interfacial Properties of Mechanoluminescent Particles in an Elastomer Matrix
Authors: Krishnan Srivatsava , Katsube Noriko , Sundaresan Vishnu baba 
Published: December 2019

Abstract
Mechanoluminescent-particulate filled composites have been gaining significant interest for light generation, stress visualization, health monitoring, damage sensing and pressure mapping applications. Previous works on stress-dependence of light emission have modeled emission intensity as a function of macroscopic composite stress. While this approach may suffice from an application point of view, the resulting model may not represent the mechanoluminescence phenomenon accurately. This is because in particulate filled elastomer composites, particulate stresses can be significantly different from matrix and macroscopic stresses, especially in composites with moderate and low filler volume fraction. Experimental difficulty in measuring stresses within micron-sized particles necessitate micromechanical models that can connect macroscale measurements to microscale parameters through material properties. Apart from the material properties of the matrix and the particles, the bonding between the two dissimilar materials at their interface influences the stress transfer significantly. Cohesive zone modeling (CZM) approach defines the interface between particles and matrix as a piecewise linear stiffness element with possible degradation of stiffness beyond a certain strain. CZM provides a convenient way to not only predict particulate stress from macroscopic stress, but also to track interface damage and debonding. In this paper, we demonstrate an experimental technique to obtain cohesive zone parameters for mechanoluminescent-particulate filled elastomer composites, utilizing optical microscopy and Digital Image Correlation (DIC). CZM thus obtained can help predict particulate stresses and aid better modeling of the mechanoluminescence phenomenon. The experimental technique can also be easily adopted for other particulate-filled composites.
Perceived Value Change via 3D Printed Bistable Structures
Authors: Chan Wan Kyn , Riley Katherine S. , Arrieta Andres F. 
Published: December 2019

Abstract
A key aspect of color change is altering perceived value or intensity. This paper presents a methodology to achieve value change through mechanical means via the deflection of bistable structures. We create mechanical pixel-based, reversible color change using 3D printed switchable bistability. Switchable bistability arises from the combination of pre-strain and shape memory, enabling us to access multiple elastically programmed shapes at elevated temperatures with fast morphing and low actuation forces, while retaining high stiffness at room temperature. Building on our previous study that achieved bistability through FDM printing with directional pre-stress, finite element analysis is conducted to design a pixel-like structure that acts as a unit cell with color change capabilities. Quantitative and qualitative analysis is conducted through image processing techniques in order to prove the viability of this approach to creating value change through geometric deformation of bistable structures. By leveraging this technique, there are numerous potential applications in fields including robotics, architecture, and interior design.
Direct Printing of a Flexible Strain Sensor for Distributed Monitoring of Deformation in Inflatable Structures
Authors: Al-Rubaiai Mohammed , Tsuruta Ryohei , Nam Taewoo , Gandhi Umesh , Tan Xiaobo 
Published: December 2019

Abstract
Inflatable structures provide significant volume and weight savings for future space and soft robotic applications. Structural health monitoring (SHM) of these structures is essential to ensuring safe operation, providing early warnings of damage, and measuring structural changes over time. In this paper, we propose the design of a single flexible strain sensor for distributed monitoring of an inflatable tube, in particular, the detection and localization of a kink should that occur. Several commercially available conductive materials, including 3D-printing filaments, conductive paint, and conductive fabrics are explored for their strain-sensing performance, where the resistance change under uniaxial tension is measured, and the corresponding gauge factor (GF) is characterized. Flexible strain sensors are then fabricated and integrated with an inflatable structure fabric using screen-printing or 3D-printing techniques, depending on the nature of the raw conductive material. Among the tested materials, the conductive paint shows the highest stability, with GF of 15 and working strain range of 2.28%. Finally, the geometry of the sensor is designed to enable distributed monitoring of an inflatable tube. In particular, for a given deformation magnitude, the sensor output shows a monotonic relationship with the location where the deformation is applied, thus enabling the monitoring of the entire tube with a single sensor.