Current Prototype Research Articles

(Invited) Na-Ion Batteries: Challenges and Opportunities

With the ever-increasing demands of modern societies, energy generation, storage, and distribution are becoming increasingly important research fields. Currently, one of the most promising areas of research and development is Sodium ion Battery (SIB) technology, which has a range of potential applications but remains particularly suited for use in stationary systems. [1-5]. Here we will discuss SIB systems in terms of what may be considered its three most significant components: anodes, electrolytes, and cathodes. SIB anodes are mainly based on hard carbon materials, due to their attractive combination of low cost and high energy density. However, there has also been interest in other systems, such as intermetallic alloying materials and metal oxides, as well as exploiting specific electrolyte co-solvation effects so as to enable the use of graphite. In general, the SIB research community uses organic electrolytes which are analogous to already existing Lithium ion batteries (LIB). However, recently there has been growing interest in developing new electrolytes which are specifically tailored for use in SIBs, such as optimized liquid and solid electrolytes. At the present time, cathodes are one of the most explored SIB components - with a plethora of options to choose from, including Prussian blue and organic materials. However, the most promising are polyanionic and layered materials, with their good combinations of electrochemical performance, low cost, stability and available constituents. Although interest in SIB technology has only relatively new, when compared to LIBs, it has been already developed at the prototyping level. A general overview of the most interesting electrode and electrolyte materials for Na-ion batteries paying special attention to those related to the current prototypes will be presented. By examining this topic in detail, it will be shown that there exists a strong drive to exploit this technology and that there are a wide range of opportunities to develop new and improved SIB technologies.

Enabling single-site laparoscopy: the SPORT platform

BackgroundThe Single Port Orifice Robotic Technology (SPORT) Surgical System by Titan Medical Inc. is designed to overcome the inherent challenges of minimally invasive single-access procedures. The aim of this preclinical study was to evaluate the feasibility of various digestive surgery procedures using this novel surgical robotic platform.MethodsA total of 12 minimally invasive procedures were performed on six pigs (5 cholecystectomies, 3 Nissen fundoplications, 1 splenectomy and 1 hepatic pedicle dissection) and on one human cadaver (1 cholecystectomy and 1 Nissen fundoplication), by four laparoscopic surgeons. The usability of the device was assessed by means of the modified objective structured assessment of technical skills (OSATS) score that was calculated and analyzed by two independent observers on the recorded videos. Surgeon feedback and recommendations were systematically recorded.ResultsAll procedures were successfully completed with the SPORT system. In general, surgeons reported to appreciate the intuitive interface and controls, the high-resolution 3D imaging, the dexterity of the end-effectors, and the ergonomic open control platform. Some features requiring optimization were also identified. The modified OSATS score demonstrated a learning curve effect for all device-related tasks.ConclusionsA variety of abdominal procedures could be safely completed with the current SPORT prototype, in the preclinical setting. This preliminary feasibility experience is promising and encourages further development of single-port robotically assisted surgery.

A compliantly coupled dielectric elastomer actuator using magnetic repulsion

Dielectric elastomer actuators (DEAs) have attracted growing research interest over the past two decades for their large actuation strain, inherent compliance, and low cost. The conical DEA configuration is particularly attractive thanks to their simple structure and high force/stroke actuation. A double cone DEA design with two antagonistic membranes allows active bidirectional actuation. However, in existing double cone DEA designs, the two membranes are rigidly coupled, which restricts their relative actuation response under periodic electrical input to 180° out-of-phase operation. This work presents a magnetically coupled DEA with compliant coupling by a magnetic repulsion. The compliant coupling allows two separate inputs with a fully adjustable phase difference. The current prototype demonstrates a peak normalized stroke of 14% (relative to the nominal DEA height) at a phase shift of 180° and a normalized linear expansion between the two membranes of up to 8.3% (relative to the nominal DEA height) at a phase shift of 0° at 0.5 Hz. This results in several emerging actuation behaviors, which could potentially be suitable for controllable shape changing actuations, active vibration damping, and bioinspired locomotion.

Towards an Event Streaming Service for ATLAS data processing

The ATLAS experiment at the LHC is gradually transitioning from the traditional file-based processing model to dynamic workflow management at the event level with the ATLAS Event Service (AES). The AES assigns finegrained processing jobs to workers and streams out the data in quasi-real time, ensuring fully efficient utilization of all resources, including the most volatile. The next major step in this evolution is the possibility to intelligently stream the input data itself to workers. The Event Streaming Service (ESS) is now in development to asynchronously deliver only the input data required for processing when it is needed, protecting the application payload fromWAN latency without creating expensive long-term replicas. In the current prototype implementation, ESS processes run on compute nodes in parallel to the payload, reading the input event ranges remotely over the network, and replicating them in small input files that are passed to the application. In this contribution, we present the performance of the ESS prototype for different types of workflows in comparison to tasks accessing remote data directly. Based on the experience gained with the current prototype, we are now moving to the development of a server-side component of the ESS. The service can evolve progressively into a powerful Content Delivery Network-like capability for data streaming, ultimately enabling the delivery of ‘virtual data’ generated on demand.

Recent Status and Future Prospects of Coaxial-Cavity Gyrotron Development at KIT

Coaxial-cavity gyrotrons are microwave sources that can extend the possible power levels of hollow cavity gyrotrons significantly and make them attractive for future fusion experiments and power plants. KIT already demonstrated operation of a modular short-pulse 170 GHz coaxial-cavity gyrotron with an output power of 2.2 MW, operating in the TE34,19mode. Today’s focus of KIT is the verification of this technology at longer pulses, which will prove the long-pulse capabilities also. At the moment, the current KIT prototype has been extended with cooling capabilities for all critical, highly loaded components of the tube and two new, different electron guns are available for operation. This paper will give an overview about the recent status and the future prospects connected to the coaxial-cavity gyrotron development at KIT, including both experimental and theoretical activities.

Virtual Model of Grip-and-Cut Picking for Simulation of Vibration and Falling of Grape Clusters

Abstract. Current robotic prototypes mainly harvest fruit clusters by gripping and cutting the main rachis. However, severe cluster vibration and fruit falling may occur during speedy harvesting. Determining the characteristics of this vibration and falling is important to achieve optimal control in robotic harvesting. Therefore, a virtual grip-and-cut model of cluster picking was developed, and corresponding cluster vibration and fruit falling simulations were performed for robotic harvesting. Multi-property finite element modeling of the main rachis was based on measurements of the rachis compression, shearing, and bending properties. A simulation model of cluster vibration was then built and combined with an end-effector model to obtain a virtual model of grip-and-cut cluster picking. The 3D vibration simulation model of a fruit cluster coupled with the grip-and-cut end-effector model effectively characterized the complex vibration in multilevel and multicomponent fruit clusters with individual diversity of the components’ properties. With the virtual model for cluster picking, dynamic interactive simulation can be realized of the fruit cluster and the grip-and-cut end-effector. Experiments verified that the average deviation of the average swing angle and fruit falling ratio were 6.09% and 8.71%, respectively. Furthermore, the finger-rachis deviation and grip-and-cut speed had a significant influence on the swing angle and fruit falling ratio. The 3D vibration simulation model of a fruit cluster and the virtual model of cluster picking are useful tools for virtual analysis and design of robotic harvesters. Keywords: Falling, Fruit cluster, Harvesting, Robot, Simulation, Vibration.

Pre-Clinical Translation of Second Harmonic Microscopy of Meniscal and Articular Cartilage Using a Prototype Nonlinear Microendoscope.

Previous studies using nonlinear microscopy have demonstrated that osteoarthritis (OA) is characterized by the gradual replacement of Type II collagen with Type I collagen. The objective of this study was to develop a prototype nonlinear laser scanning microendoscope capable of resolving the structural differences of collagen in various orthopaedically relevant cartilaginous surfaces. The current prototype developed a miniaturized femtosecond laser scanning instrument, mounted on an articulated positioning system, capable of both conventional arthroscopy and second-harmonic laser-scanning microscopy. Its optical system includes a multi-resolution optical system using a gradient index objective lens and a customized multi-purpose fiber optic sheath to maximize the collection of backscattered photons or provide joint capsule illumination. The stability and suitability of the prototype arthroscope to approach and image cartilage were evaluated through preliminary testing on fresh, minimally processed, and partially intact porcine knee joints. Image quality was sufficient to distinguish between hyaline cartilage and fibrocartilage through unique Type I and Type II collagen-specific characteristics. Imaging the meniscus revealed that the system was able to visualize differences in the collagen arrangement between the superficial and lamellar layers. Such detailed in vivo imaging of the cartilage surfaces could obviate the need to perform biopsies for ex vivo histological analysis in the future, and provide an alternative to conventional external imaging to characterize and diagnose progressive and degenerative cartilage diseases such as OA. Moreover, this system is readily customizable and may provide a suitable and modular platform for developing additional tools utilizing femtosecond lasers for tissue cutting within the familiar confines of two or three portal arthroscopy techniques.

Information and communication technologies support for the participation of universities in innovation networks (comparative study)

To ensure and strengthen the development of high-tech R&D and its industrial applications in the long-term perspective, information and communication technologies (ICT) cooperation tools with national and international institutions, network associations and firms are of great importance. To solve this problem, a joint systematic and coordinated work to develop institutions that can provide crucial support to innovation process is crucial. For these purposes, higher educational institutions (HEI) innovation activities information and communication support and technological development analysis are critically important. The purpose of this study is to analyze the existing ICT toolkit, which is used to manage R&D and various industrial applications, and to develop a conceptual framework for the implementation of these tools for the participation of universities in innovation networks. To answer this question, authors begin by taking a closer look at the new role of universities in the development of knowledge generation in a global environment, as well as problems and tendencies under conditions of postindustrial society. The new role of universities in knowledge generation in the global environment development, and problems and tendencies under the conditions of postindustrial society were outlined. Modern ICT components, which are necessary for universities to participate in the innovation networks, were analyzed. Some cases of foreign experience in the scientific and innovation networks of current prototypes of Industry 4.0 development were discussed, and the possibilities of its adaptation to national innovation system formation conditions in Ukraine were identified. By theoretical and empirical examining, the authors propose more complete understanding of modern ICT components, which are necessary for universities to participate in innovation networks. Cases of foreign experience in the scientific and innovation networks of current prototypes of Industry 4.0 development were investigated. Moreover, the evidence from this study suggests a variety of factors related to the possibilities to adapt ICT tools to national innovation system formation in Ukraine.

Using mixed reality displays for observational learning of motor skills: A design research approach enhancing memory recall and usability

When learning an action sequence, observing a demonstration informs the knowledge of movement execution and enhances the efficiency of motor skill acquisition. Three-dimensional (3D) virtual learning environments offer more opportunities for motor skill training as they afford observational learning. Mixed reality platforms (virtual reality, desktop PC, etc.) that render 3D virtual environments can therefore increase accessibility of observational content. To explore the effectiveness of these platforms so as to facilitate observational learning of action sequences, we developed the Recovery Position Application [ 1 ] (RPA) at the Interactive System Studio, University of Plymouth. The RPA was originally designed for mobile virtual reality. The RPA displays two virtual avatars performing the steps of the recovery position. We present the design of content and interaction informed by research into observational learning of motor skills. To formatively evaluate the current functional prototype, and potential use within an educational context, RPA was tested on three different platforms. Mobile VR (N=20), desktop PC (N=20) and video recording (N=21). Memory recall of movements was recorded and the usability of the RPA was investigated. Across all three platforms, the average recall of demonstrated information was 61.88%, after using the application for 10 min. No significant differences between recall rates were identified between platforms. Participant responses were positive or very positive for both application effectiveness as a learning resource and for ease of use. These results are discussed with regard to the future development of the RPA and guidelines for virtual demonstration content. Published: 27 November 2018 This paper is part of the special collection Mobile Mixed Reality Enhanced Learning , edited by Thom Cochrane, Fiona Smart, Helen Farley and Vickel Narayan. More papers from this collection can be found here . Citation: Research in Learning Technology 2018, 26 : 2129 - http://dx.doi.org/10.25304/rlt.v26.2129

A Food Management Based on Smart Refrigerator System

Internet of Things (IoT) conceptualizes the idea of remotely connecting and monitoring real world objects (things) through the Internet [1]. When it comes to our house, this concept can be aptly incorporated to make it smarter, safer and automated. This IoT paper focuses on smart refrigerator system which sends alerts to the user when the milk packets count to be decreased because the user refilling he packet purpose. The advantage of smart system is to maintaining the performance and avoids unavailability of milk. Besides, the same can also be utilized for smart fridge by making use of the sensors. The leverage obtained by preferring this system over the similar kinds of existing systems is that the alerts and the status sent by the wifi connected microcontroller managed system can be received by the user on his phone from any distance irrespective of whether his mobile phone . The microcontroller used in the current prototype which comes with an embedded micro-controller and an onboard Wi-Fi shield making use of which all the electrical appliances inside the home can be controlled and managed.

Fast Fourier Transformed Twin Table Ladder Modulation on Recognising Non Invasive Blood Glucose Level Measurement Optical Device Spectral Responses

A comparative trial conducted between February 2017 and April 2017, at Electronic Material Physics Laboratory, Department of Physics, Bogor Agricultural University, West Java, Indonesia. Blood spectral data from participant older than 17 years were assigned to single measurement group. Blood spectral data previously taken from All participant modulated using Twin Table and Ladder (TTL) methods, and further transformed using Fast Fourier Transform (FFT) Methods, and inferred using Fast Artificial Neural Network. The data contained blood glucose level measurement using both prototype of non invasive blood glucose level measurement optical device (prototype) and veni puncture spectrophotometry (veni). The objective was to measure effect of FFT on accuracy of TTL based optical spectral parser engine for prototype compared to veni for fasting normo glucose participants (participants). Main outcome measure: accuracy as rooted means squared error (RMSE) of either TTL and FFT - TTL inference method, smaller is better. Clarke error grid analysis (ega) and Parker ega, and sensitivity and specificity are calculated from the outcomes, larger is better. No randomization of records. The data was inferred using TTL method, and further transformed using FFT method. Analyser are not blinded for either measurement methods. 120 blood spectrum data from volunteerd included in measurement group. The trial is completed for current prototype version, and shall be reopened for future versions. 110 datums were included in the analysis of the primary outcome. RMSE of FFT-TTL 5.16 mg / dl is smaller than TTL 5.27 mg / dl. No difference between Parkes ega of FFT-TTL and pure TTL. There is insignificant increase in Clarke ega, 99.5 % group A in FFT-TTL compared to 99.3 % group A in TTL. There significance increase of specificity (0.76) but also decrease of sensitivity (0.65) of FFT-TTL compared to TTL. (0.67 and 9.72). Diagnostic accuracy (0.71) and odd ratio (5.83), and Youden index (0.41) remain not changed. No apparent possible case for adverse effect for either methods. No Significant Performance Difference on Fast Fourier Transformed Twin Table Ladder Modulation on Recognising Non Invasive Blood Glucose Level Measurement Optical Device Spectral Responses.

Eave ribbons treated with the spatial repellent, transfluthrin, can effectively protect against indoor-biting and outdoor-biting malaria mosquitoes

BackgroundLong-lasting insecticide-treated nets and indoor residual spraying protect against indoor-biting and indoor-resting mosquitoes but are largely ineffective for early-biting and outdoor-biting malaria vectors. Complementary tools are, therefore, needed to accelerate control efforts. This paper describes simple hessian ribbons treated with spatial repellents and wrapped around eaves of houses to prevent outdoor-biting and indoor-biting mosquitoes over long periods of time.MethodsThe eave ribbons are 15 cm-wide triple-layered hessian fabrics, in lengths starting 1 m. They can be fitted onto houses using nails, adhesives or Velcro, without completely closing eave-spaces. In 75 experimental nights, untreated ribbons and ribbons treated with 0.02%, 0.2%, 1.5% or 5% transfluthrin emulsion (spatial repellent) were evaluated against blank controls using two experimental huts inside a 202 m2 semi-field chamber where 500 laboratory-reared Anopheles arabiensis were released nightly. Two volunteers sat outdoors (one/hut) and collected mosquitoes attempting to bite them from 6 p.m. to 10 p.m. (outdoor-biting), then went indoors and slept under bed nets, beside which CDC-light traps collected mosquitoes from 10 p.m. to 6.30 a.m. (indoor-biting). To assess survival, 200 caged mosquitoes were suspended near the huts nightly and monitored for 24 h thereafter. Additionally, field tests were done in experimental huts in a rural Tanzanian village to evaluate treated ribbons (1.5% transfluthrin). Here, indoor-biting was assessed using window traps and Prokopack® aspirators, and outdoor-biting assessed using volunteer-occupied double-net traps.ResultsIndoor-biting and outdoor-biting decreased > 99% in huts fitted with eave ribbons having ≥ 0.2% transfluthrin. Even 0.02% transfluthrin-treated ribbons provided 79% protection indoors and 60% outdoors. Untreated ribbons however reduced indoor-biting by only 27% and increased outdoor-biting by 18%, though these were non-significant (P > 0.05). Of all caged mosquitoes exposed near treated huts, 99.5% died within 24 h. In field tests, the ribbons provided 96% protection indoors and 84% outdoors against An. arabiensis, plus 42% protection indoors and 40% outdoors against Anopheles funestus. Current prototypes cost ~ 7USD/hut, are made of widely-available hessian and require no specialized expertise.ConclusionTransfluthrin-treated eave ribbons significantly prevented outdoor-biting and indoor-biting malaria vectors and could potentially complement current tools. The technique is simple, low-cost, highly-scalable and easy-to-use; making it suitable even for poorly-constructed houses and low-income groups.

Navigation and visualisation with HoloLens in endovascular aortic repair.

IntroductionEndovascular aortic repair (EVAR) is a minimal-invasive technique that prevents life-threatening rupture in patients with aortic pathologies by implantation of an endoluminal stent graft. During the endovascular procedure, device navigation is currently performed by fluoroscopy in combination with digital subtraction angiography. This study presents the current iterative process of biomedical engineering within the disruptive interdisciplinary project Nav EVAR, which includes advanced navigation, image techniques and augmented reality with the aim of reducing side effects (namely radiation exposure and contrast agent administration) and optimising visualisation during EVAR procedures. This article describes the current prototype developed in this project and the experiments conducted to evaluate it.MethodsThe current approach of the Nav EVAR project is guiding EVAR interventions in real-time with an electromagnetic tracking system after attaching a sensor on the catheter tip and displaying this information on Microsoft HoloLens glasses. This augmented reality technology enables the visualisation of virtual objects superimposed on the real environment. These virtual objects include three-dimensional (3D) objects (namely 3D models of the skin and vascular structures) and two-dimensional (2D) objects [namely orthogonal views of computed tomography (CT) angiograms, 2D images of 3D vascular models, and 2D images of a new virtual angioscopy whose appearance of the vessel wall follows that shown in ex vivo and in vivo angioscopies]. Specific external markers were designed to be used as landmarks in the registration process to map the tracking data and radiological data into a common space. In addition, the use of real-time 3D ultrasound (US) is also under evaluation in the Nav EVAR project for guiding endovascular tools and updating navigation with intraoperative imaging. US volumes are streamed from the US system to HoloLens and visualised at a certain distance from the probe by tracking augmented reality markers. A human model torso that includes a 3D printed patient-specific aortic model was built to provide a realistic test environment for evaluation of technical components in the Nav EVAR project. The solutions presented in this study were tested by using an US training model and the aortic-aneurysm phantom.ResultsDuring the navigation of the catheter tip in the US training model, the 3D models of the phantom surface and vessels were visualised on HoloLens. In addition, a virtual angioscopy was also built from a CT scan of the aortic-aneurysm phantom. The external markers designed for this study were visible in the CT scan and the electromagnetically tracked pointer fitted in each marker hole. US volumes of the US training model were sent from the US system to HoloLens in order to display them, showing a latency of 259±86 ms (mean±standard deviation).ConclusionThe Nav EVAR project tackles the problem of radiation exposure and contrast agent administration during EVAR interventions by using a multidisciplinary approach to guide the endovascular tools. Its current state presents several limitations such as the rigid alignment between preoperative data and the simulated patient. Nevertheless, the techniques shown in this study in combination with fibre Bragg gratings and optical coherence tomography are a promising approach to overcome the problems of EVAR interventions.

Protecting quantum resources via frequency modulation of qubits in leaky cavities

Finding strategies to preserve quantum resources in open systems is nowadays a main requirement for reliable quantum-enhanced technologies. We address this issue by considering structured cavities embedding qubits driven by a control technique known as frequency modulation. We first study a single qubit in a lossy cavity to determine optimal modulation parameters and qubit-cavity coupling regime allowing a gain of four orders of magnitude concerning coherence lifetimes. We relate this behavior to the inhibition of the qubit effective decay rate rather than to stronger memory effects (non-Markovianity) of the system. We then exploit these findings in a system of noninteracting qubits embedded in separated cavities to gain basic information about scalability of the procedure. We show that the determined modulation parameters enable lifetimes of quantum resources, such as entanglement, discord and coherence, three orders of magnitude longer than their natural (uncontrolled) decay times. We discuss the feasibility of the system within the circuit-QED scenario, typically employed in the current quantum computer prototypes. These results provide new insights towards efficient experimental strategies against decoherence.

Al-light

Inappropriate alcohol drinking may cause health and social problems. Although controlling the intake of alcohol is effective to solve the problem, it is laborious to track consumption manually. A system that automatically records the amount of alcohol consumption has a potential to improve behavior in drinking activities. Existing devices and systems support drinking activity detection and liquid intake estimation, but our target scenario requires the capability of determining the alcohol concentration of a beverage. We present Al-light, a smart ice cube to detect the alcohol concentration level of a beverage using an optical method. Al-light is the size of 31.9 x 38.6 x 52.6 mm and users can simply put it into a beverage for estimation. It embeds near infrared (1450 nm) and visible LEDs, and measures the magnitude of light absorption. Our device design integrates prior technology in a patent which exploits different light absorption properties between water and ethanol to determine alcohol concentration. Through our revisitation studies, we found that light at the wavelength of 1450 nm has strong distinguishability even with different types of commercially-available beverages. Our quantitative examinations on alcohol concentration estimation revealed that Al-light was able to achieve the estimation accuracy of approximately 2 % v/v with 13 commercially-available beverages. Although our current approach needs a regressor to be trained for a particular ambient light condition or the sensor to be calibrated using measurements with water, it does not require beverage-dependent models unlike prior work. We then discuss four applications our current prototype supports and future research directions.

The strength and spread of the electric field induced by transcranial rotating permanent magnet stimulation in comparison with conventional transcranial magnetic stimulation

BackgroundWeak or low intensity transcranial stimulation of the brain, such as low field magnetic stimulation and electrical stimulation, can produce significant functional and therapeutic neuromodulatory effects. New methodWe have recently developed a portable wearable multifocal brain stimulator called transcranial rotating permanent magnet stimulator (TRPMS) that uses rapidly spinning high field strength permanent magnets attached to a cap. It produces oscillatory stimuli of different frequencies and patterns. Here we compared the strengths and spatial profiles of the changing magnetic fields of a figure-of-eight transcranial magnetic stimulator (TMS) coil, a TRPMS prototype, and a scaled-up version of TRPMS. We measured field strengths and directions of voltages induced in a magnetic field sensor oriented along all three orthogonal axes. Results and comparison with existing methodsThe spatial spread of the TRPMS-induced electric field is more restricted, and its shape and strength vary less with the orientation of the inductance than TMS. The maximum voltage induced by the current prototype is ∼7% of the maximal TMS output at depths corresponding to the human cerebral cortex from the scalp surface. This field strength can be scaled up by a factor ∼8 with a larger diametrically magnetized magnet. These comparative data allow us to estimate that intracortical effects of TRPMS could be stronger than other low intensity stimulation methods. ConclusionsTRPMS might enable greater uniformity, consistency and focality in stimulation of targeted cortical areas subject to significant anatomical variability. Multiple TRPMS microstimulators can also be combined to produce patterned multifocal spatiotemporal stimulation.

Test Results of ITER 52-kA HTS Current Lead Prototypes

The Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) is responsible for the construction and performance testing of the 30 pairs of the international thermonuclear experimental reactor high-temperature superconducting (HTS) current leads. The first pair of poloidal field (PF) coil type, 52-kA HTS current lead prototypes was built and cold tested in ASIPP in mid-2016. The test results demonstrated their excellent performance on low joint resistance, long loss of flow accident time, and high current-sharing temperature. The overheating time, mass flow, and heat loads to 5-K ends also meet the requirements. This paper summarizes the major test results for the PF 52-kA HTS current lead prototypes.

A wide-range DC current sensing method based on disk-type magnetoelectric laminate composite and magnetic concentrator

A DC current sensing method is developed by introducing the controllable sensitivity. The prototype sensor is implemented by inserting a transverse-transverse (T-T) mode disk-type magnetoelectric (ME) laminate into the air gap of a C-shaped ferrite magnetic concentrator to measure a wide range DC current. The equivalent circuit model of the ME laminate containing interface coupling factor, which physically reflects the strain transfer between the phases, has been further applied in DC current sensing under both low and resonant frequency excitation in this paper. The theoretical analysis results indicate that the DC current sensitivity is controllable by setting the quiescent operating point on the d31,m-Hbias curve of Terfenol-D and the excitation frequency of the ME laminate, respectively. Under 1 Oe AC magnetic field drive at 1 kHz, the DC current sensitivity dVac/dIdc of this DC current prototype sensor is 0.058 mV/A, equivalently 0.124 mV/Oe over the range of 0–500 A. Under resonant frequency AC magnetic drive, the current sensitivity dVac/dIdc = 2.38 mV/A, equivalently 5.12 mV/Oe over the same current range, considerably higher than that reported in previous DC ME sensor literatures. The experimental results provide a potential strategy for realizing wide-range DC current sensing in real applications. For lower current measurement, this ME based DC sensor should be operated under resonant excitation to obtain a high voltage output, while for higher current, it can be switched to be operated at a proper quiescent operating point under non-resonant frequency for an acceptable output.

Artworks in the spotlight: characterization with a multispectral LED dome

We describe the design and realization of a novel multispectral light dome system and the associated software control and calibration tools used to process the acquired data, in a specialized pipeline geared towards the analysis of shape and appearance properties of cultural heritage items. The current prototype dome, built using easily available electronic and lighting components, can illuminate a target of size 20cm x 20cm from 52 directions uniformly distributed in a hemisphere. From each illumination direction, 3 LED lights cover the visible range of the electromagnetic spectrum, as well as long ultraviolet and near infrared. A dedicated control system implemented on Arduino boards connected to a controlling PC fully manages all lighting and a camera to support automated acquisition. The controlling software also allows real-time adjustment of the LED settings, and provides a live-view of the to-be-captured scene. We approach per-pixel light calibration by placing dedicated targets in the focal plane: four black reflective spheres for back-tracing the position of the LED lamps and a planar full-frame white paper to correct for the non-uniformity of radiance. Once the light calibration is safeguarded, the multispectral acquisition of an artwork can be completed in a matter of minutes, resulting in a spot-wise appearance profile, that stores at pixel level the per-frequency intensity value together with the light direction vector. By performing calibrated acquisition of multispectral Reflectance Transformation Imaging (RTI), with our analysis system it is possible to recover surface normals, to characterize matte and specular behavior of materials, and to explore different surface layers thanks to UV-VIS-IR LED light separation. To demonstrate the system features we present the outcomes of the on-site capture of metallic artwork at the National Archaeological Museum of Cagliari, Sardinia.

Collaborative Findings on Manufacturing Needs for Biofabrication of Engineered Tissues and Organs

Since its inception as a field in the late 1990s, tissue engineering and regenerative medicine (TERM) has struggled to deliver on the promises of transformative medical technologies to repair, replace, or regenerate tissues and organs damaged by disease, congenital defect, age, or trauma. Some stagnation in the TERM field is due to the inability to engage in manufacturing of these products on a large scale and/or with reliability. Unlike small-molecule drugs or medical devices, the technology to create and manufacture TERM products is complex and can be highly variable. One example of this is 3D bioprinting, which is described as the use of three-dimensional (3D) printers to create tissue engineering scaffolds or print tissues and organs with or without live cells. To discuss the issues surrounding large-scale biomanufacturing of TERM products using bioprinting technology, the University of Minnesota held a 1-day workshop on “Manufacturing Needs for Biofabrication of Engineered Tissues and Organs” in conjunction with the annual “Design of Medical Devices” conference. Through a series of talks from industry experts and breakout sessions, attendees developed problem statements and next steps for the use of bioprinting in a biomanufacturing process in five areas: unit operations in biomanufacturing, scaling and automation, bioprinting for engineered tissues, the role of standards in bioprinting, and technological gaps in bioprinting. Finally, workshop participants emphasized the need for quality raw materials, consensus standards, and process workflow optimization throughout biomanufacturing, but especially for processes that use bioprinting technology. Recent efforts by TERM-focused public-private partnerships like the BioFabUSA program will help address the challenges identified in the workshop to make bioprinting a bona fide biomanufacturing process and TERM products a viable hope for patients. A one-day conference brought together experts in industry and academia to discuss what is needed to bring biofabrication from its current prototype stage to reproducible, manufactured tissue and organ products in the future.