Sensor Concept Research Articles

Unique Device Identification–Based Linkage of Hierarchically Accessible Data Domains in Prospective Surgical Hospital Data Ecosystems: User-Centered Design Approach

The electronic health record (EHR) targets systematized collection of patient-specific, electronically stored health data. The EHR is an evolving concept driven by ongoing developments and open or unclear legal issues concerning medical technologies, cross-domain data integration, and unclear access roles. Consequently, an interdisciplinary discourse based on representative pilot scenarios is required to connect previously unconnected domains. We address cross-domain data integration including access control using the specific example of a unique device identification (UDI)-expanded hip implant. In fact, the integration of technical focus data into the hospital information system (HIS) is considered based on surgically relevant information. Moreover, the acquisition of social focus data based on mobile health (mHealth) is addressed, covering data integration and networking with therapeutic intervention and acute diagnostics data. In addition to the additive manufacturing of a hip implant with the integration of a UDI, we built a database that combines database technology and a wrapper layer known from extract, transform, load systems and brings it into a SQL database, WEB application programming interface (API) layer (back end), interface layer (rest API), and front end. It also provides semantic integration through connection mechanisms between data elements. A hip implant is approached by design, production, and verification while linking operation-relevant specifics like implant-bone fit by merging patient-specific image material (computed tomography, magnetic resonance imaging, or a biomodel) and the digital implant twin for well-founded selection pairing. This decision-facilitating linkage, which improves surgical planning, relates to patient-specific postoperative influencing factors during the healing phase. A unique product identification approach is presented, allowing a postoperative read-out with state-of-the-art hospital technology while enabling future access scenarios for patient and implant data. The latter was considered from the manufacturing perspective using the process manufacturing chain for a (patient-specific) implant to identify quality-relevant data for later access. In addition, sensor concepts were identified to use to monitor the patient-implant interaction during the healing phase using wearables, for example. A data aggregation and integration concept for heterogeneous data sources from the considered focus domains is also presented. Finally, a hierarchical data access concept is shown, protecting sensitive patient data from misuse using existing scenarios. Personalized medicine requires cross-domain linkage of data, which, in turn, require an appropriate data infrastructure and adequate hierarchical data access solutions in a shared and federated data space. The hip implant is used as an example for the usefulness of cross-domain data linkage since it bundles social, medical, and technical aspects of the implantation. It is necessary to open existing databases using interfaces for secure integration of data from end devices and to assure availability through suitable access models while guaranteeing long-term, independent data persistence. A suitable strategy requires the combination of technical solutions from the areas of identity and trust, federated data storage, cryptographic procedures, and software engineering as well as organizational changes.

A tactile and airflow motion sensor based on flexible double-layer magnetic cilia

Inspired by the concept of bionics, a tactile and airflow motion sensor based on flexible double-layer magnetic cilia is developed, showing extremely high sensitivity in both force and airflow detection. The upper layer of the magnetic cilia is a flexible material mixed with magnetic particles, while the lower layer is a pure flexible material. This double-layer structure significantly improves magnetism while maintaining cilia flexibility. In addition, a metal tube pressing (MTP) method is proposed to overcome the difficulties in preparing large aspect ratio (over 30:1) cilia, offering simplicity and avoiding the use of large-scale MEMS instruments. The developed sensor has a detection range between 0 and 60 µN with a resolution of 2.1 µN for micro forces. It also shows great detection ability for airflow velocity with a sensitivity of 1.43 µT/(m/s). Experiments show that the sensor could be applied in surface roughness characterization and sleep apnea monitoring.

Terrain segmentation for commercial vehicles and working machines

In the field of automated working machines, not only is the general trend towards automation in industry, transport and logistics reflected, but new areas of application and markets are also constantly emerging. In this paper we present a pipeline for terrain classification in offroad environments and in the field of "automated maintenance of slopes", which offers potential for solving numerous socio-economic needs. Working tasks can be made more efficient, more ergonomic and, in particular, much safer, because mature, automated vehicles are used. At present, however, such tasks can only be carried out remotely or semi-automatically, under the supervision of a trained specialist. This only partially facilitates the work. The real benefit only comes when the supervising person is released from this task and is able to pursue other work. In addition to the development of a safe integrated system and sensor concept for use in public spaces as a basic prerequisite for vehicles licensed in the future, increased situational awareness of mobile systems through machine learning in order to increase their efficiency and flexibility is also of great importance.

Technical concepts of automotive LiDAR sensors: a review

Automotive LiDAR sensors are seen by many as the enabling technology for higher-level autonomous driving functionalities. Different concepts to design such a sensor can be found in the industry. Some have already been integrated into consumer cars while many others promise to be in mass production soon to become cost-effective enough for broad deployment. However, automotive LiDAR sensors are still evolving and a variety of sensor designs are pursued by different companies. Here, we construct the automotive LiDAR design space to visually depict system design options for these sensors. Subsequently, we exemplify the concepts with drawings that can be found in published patent applications (focusing on scanning mechanisms and scan patterns) before discussing their advantages and challenges.

Field evaluation of a novel holographic single-image depth reconstruction sensor

A camera-based single-image sensor is presented, that is able to measure the distance of one or multiple object points (light emitters). The sensor consists of a camera, whose lens is upgraded with a diffractive optical element (DOE). It fulfils two tasks: adding a vortex point spread function (PSF) and replication of the vortex PSFs to a predefined pattern of K spots. Both, shape and rotation of the vortex PSF is sensitive to defocus. The sensor concept is presented and its capabilities evaluated both on axis and off-axis. The achieved standard deviation of the error ranges between 8.5 μm (on-axis) and 3.5 μm (off-axis) within a measurement range of 20 mm. However, as soon as calibration and measurement position no longer match, the accuracy is limited. An analysis of the effects responsible for this are also part of the publication.

Low-Cost Predictive Maintenance Monitoring Concept for Forming Presses

The digitisation of existing industrial plants is often a distant goal for small and medium-sized companies. However, intelligent sensor equipment and evaluation is important to improve overall production quality and therefore be competitive with companies operating modern equipment. The focus of this work is the digitisation of forming presses to optimise both maintenance and production quality at a reasonable cost. For this reason, a sensor concept is being developed for monitoring the various states of forming presses. The resulting concept will eventually be integrated into a forming press at an industrial production site.

A Liquid Sensor Based on Frequency Selective Surfaces

A novel, simple and easy-to-fabricate liquid sensor using frequency-selective surfaces (FSSs) is proposed. The new sensor concept is based on modifying the capacitance between adjacent FSS elements when materials of different electrical characteristics are inserted. The change in capacitance produces a change in resonant frequency. The FSS design consists of a 9 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 9 array of square loops on <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.31\lambda \times 0.31\lambda $ </tex-math></inline-formula> square unit cells with trenches between the loops. The trenches are filled with liquids under test (LTUs). The structure operates at 4.6 GHz without any liquid. When liquids are inserted in the trenches, the resonance frequency varies in relation to the dielectric constant of the liquid. This is observed by measuring the transmission coefficient ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S_{21}$ </tex-math></inline-formula> ). Butan-1-ol, ethanol, methanol, propan-2-ol, and xylene are used to demonstrate the sensing function. A maximum sensitivity of 8.65% for xylene was achieved. Furthermore, very low differences were observed between the measured and expected dielectric constant and loss tangent, thus validating the design. The device is inexpensive, compact, and easy to make and scalable for large-area operations in liquid detection for microwave sensing applications. This technique has potential applications in reconfigurable FSS.

NonInvasive Glucose Fiber Sensor Based on Self-Imaging Technique: Proof of Concept

This paper proposes a proof of concept for a reflective fiber optic sensor based on multimode interference, designed to measure glucose concentrations in aqueous solutions that mimic the range of glucose concentrations found in human saliva. The sensor is fabricated by splicing a short section of coreless silica fiber into a standard single-mode fiber. By studying the principles of multimode interference and Self-imaging it was developed a sensing head that has a total length of 29.1 mm, approximately equal to the second self-image cycle. This sensing head allowed us to detect low concentrations of glucose (ranging from 0 to 268 mg/dl).

Data-driven development of sparse multi-spectral sensors for urological tissue differentiation

Infrared spectroscopy is often used to spot differences between benign and malignant tissue. Due to the proliferation of tumorous cells, the composition of tissue changes drastically. In the consequence shifts occur in its optical properties that are indicated by spectral biomarkers in the so-called fingerprint region. In this work, we propose a new concept for a sparsified multi-spectral measurement of the most important and informative biomarker signals. The results of a data-driven feature selection approach show that a reliable discrimination of the tissue is still possible, even though utilizing only a small fraction of the measured data. A selected arrangement of only a few narrow-band quantum cascade lasers could provide proficient signal-to-noise ratios and can noticeably reduce the data acquisition time. Consequentially, real-time applications will be possible in short-term and in-vivo diagnostics in the long-term. First measurements of silicone phantoms validate the imaging capability of the sensor concept.

Coupled Optical Resonances in a Dielectric Microsphere: Physical Concept of a Miniature Optical Pressure Sensor

Coupled Optical Resonances in a Dielectric Microsphere: Physical Concept of a Miniature Optical Pressure Sensor

Polymer indicator displacement assay (PIDA) with boronic acid receptors on graphene foam electrodes for self-optimised impedimetric lactic acid determination

Synthetic organic receptor molecules are employed based on boronic acids attached to graphene to provide functionality and selectivity in competitive analyte binding. Here, a new electrochemical sensor concept based on a surface redox polymer indicator displacement (avoiding traditional solution redox indicators) is proposed and demonstrated on graphene foam electrodes. A pyrene-derivatised boronic acid chemo-receptor for lactic acid is adsorbed onto graphene foam and coated with poly-nordihydroguaiaretic acid (poly-NHG) as an electrochemically active polymer indicator. When bound to the boronic acid, poly-NHG remains redox silent. Dynamic displacement with lactic acid results in a concentration-dependent Faradaic current response. Effects of pH and detection methodology (voltammetry, chronoamperometry, and impedance spectroscopy) are investigated. Self-optimised impedimetric sensing based on the interfacial electron transfer resistance is demonstrated. While lactic acid sensing in human serum is possible, the sensor response is lower. Surface-active components from human serum are shown to modify the sensor response without affecting performance. Lactic acid sensing in artificial sweat at pH 4.7 is shown to result in a Langmuirian binding curve with apparent binding constant K = 40 M-1.

A review on smart aggregate based structural health monitoring

Concrete structures are prone to damage and deterioration in their health due to environmental effects, aging, etc., leading to failure prior to their intended service life. Structural Health Monitoring (SHM) is an innovative technique adopted for assessing the structural health, damage identification and assessing the residual life of the structure. The conventional techniques have proved to be inefficient as they required prior information about the vicinity of the damage and accessibility to the damaged region of the structure. The development of various sensors such as fiber optical sensor (FOS), piezoelectric transducers have proved to efficient. This study presents the introduction and the fundamental concept of the latest sensor in trend in the domain of SHM, the piezoceramic-based Smart Aggregate(SA). The applications of SA under various loadings for concrete structures have been reviewed. Also, the damage indices developed for 1-D and 2-D structural components for assessing the damage status in the structure have been summarized. It was established that the smart aggregate is capable of damage detection, health monitoring (concrete columns, shear wall, frames) and impact detection(concrete piles).

Tackling the challenges of developing microneedle-based electrochemical sensors.

Microneedles provide unique advantages in biomedical areas, particularly biosensing, because of their opportunities for minimally invasive and convenient detection. This review introduces concepts of electrochemical microneedle-based sensors for minimally invasive analysis together with insights into skin compartments for designing successful microneedles. We discuss requirements for developing microneedle-based biosensors, including electrical and electrochemical behaviors of materials (such as metals, nanomaterials, and conducting polymers) which are the key factors for sensitive biosensors. We further emphasize immobilization strategies to attach biorecognition elements to electrode materials. Moreover, we detail advanced techniques that require state-of-the-art fabrications and materials to realize porous, biodegradable, and antifouling materials to enhance biosensing performances. We also emphasize studies of cytotoxicity and damage to the skin to elucidate biocompatible potentials. Furthermore, we highlight the latest advances in microneedles published from 2019 to 2022. This review also includes an overview of key remaining obstacles and opportunities where developments will push the advances continuously. The conclusion and outlook on the status of laboratory and commercial availability are added. We prospect that microneedle sensors will be integrated into a closed-loop system biodevice for diverse applications, e.g., detection and therapy. This review discusses concepts of electrochemical microneedle-based sensors for minimally invasive monitoring. We discuss requirements including geometry, mechanical, electrical, electrochemical properties, and immobilization strategy. We illustrate advanced techniques and materials to enrich biosensor features, e.g., porosity, dissolvable ability, and anti-fouling capability. Concern of toxicity is highlighted. We also illustrate recent applications and outlooks of recently published study that exploits microneedle-based biosensors.

Superconducting gravimeters based on advanced nanomaterials and quantum neural network

The paper is focused on a new concept of a cryogenic-optical sensor intended for use in the space industry, geodynamics, and fundamental experiments. The basis of the sensor is a magnetic suspension with a levitating test body, a high-precision optical recorder of mechanical coordinates of the levitating body, and a signal-processing system. A Michelson-type interferometer with a laser diode and a single-mode optical fiber was used to measure the test body's displacements. The coordination of the laser diode coherence length and the difference in the interferometer optical lengths of the arms made it possible to eliminate coherent noise caused by interference from spurious reflections. The minimum recorded shift of the test body was 0.1 nm. The design of the sensor and the mathematical model of the superconducting suspension dynamics are presented. The results of experimental studies of a magnetic suspension together with an optical interferometric displacement sensor having a subnanometer sensitivity are shown.

Integration Aspects of Plasmonic TiN-based Nano-Hole-Arrays on Ge Photodetectorsin a 200mm Wafer CMOS Compatible Silicon Technology

During the last decade optical sensor technologies have attracted increased attention for various applications. Plasmon-based optical sensor concepts for the detection of refractive index changes that rely on propagating surface-plasmon polaritons at metal-dielectric interfaces or on localized plasmons in metallic nanostructures prove their potential for these application due to their fast detection speed, high specificity and sensitivities [1, 2]. Combining plasmonic structures directly with optoelectronic devices could enable a high level of integration, however, it represents a significant technological challenge to develop an on-chip solution for these concepts including the integration of sensor and detector components. Previous works demonstrated first approaches mainly for the integration of refractive index sensor components on wafer level [3, 4]. In [5] and [6] a proof-of-concept of a fully integrated on-chip solution with high sensitivities was presented, which can be easily combined with microfluidics [7] for potential applications in biosensing. In this concept, a nanohole array (NHA) was structured in a 100 nm thick aluminum layer on top of a vertical PIN germanium photodetector (GePD) with an intrinsic germanium sheet of 480 nm. This sensor concept relies on extraordinary optical transmission through the NHA [8]: Light transmission is only possible for narrow wavelength ranges determined by the NHA geometry which determine the transmission peaks at the resonance wavelength of the NHA. Thus, the NHA acts as a high quality wavelength filter. Due to the change in the refractive index, a material under test (MUT) contacting directly the surface of the NHA, provokes a shift of the wavelength maximum, which can be detected by measuring the photocurrent spectra of the GePD. While responsivities and sensitivities of (0 V) = 0.075 A/W and = 1200 nm/RIU could be attained in this proof-of-concept device [6, 7], the semiconductor device layers were deposited using molecular beam epitaxy (MBE). Furthermore the vertical PIN GePD was realized by a mesa procedure to enable large areas for top illuminated operations. These techniques are unsuitable for an industrial CMOS fabrication process with high throughput. Therefore, the development of a CMOS compatible technology process with low costs and high yields is an important step towards large-scale fabrication of this sensor concept.In this work we present the progress for the realization of a surface plasmon resonance (SPR) refractive index sensor in a 200 mm wafer Silicon based technology. One main challenge is the fabrication of a large area photodetector for top illuminated sensor devices. We developed a process, which is mainly based on the IHP electronic photonic integrated circuits (ePIC) technology [9]. This ePIC technology enables the production of waveguide coupled lateral PIN GePDs with high bandwidth and high responsivities [10]. However, these PDs are unsuitable for top illuminated applications because of their small germanium areas. Due to certain process conditions with respect to chemical mechanical polishing procedures there are limits for feasible large detector areas. Furthermore, large detector areas for lateral PIN GePDs would result in very low electric fields in the intrinsic zone where carriers are generated by photon absorption. Thus, very high voltages for reversed bias are necessary for sufficient carrier drifts.For the first time we have developed a modern detector design concept which is compatible to the IHP ePIC technology. This concept allows the realization of large area detectors of 1600µm² (40µm x 40µm) with optimized optical responsivities for top illuminated applications. The detector consists of several parallel connected lateral PIN GePDs. We designed different variations and varied Ge width and distance between neighboring GePDs in order to investigate process limits. The p- and n-doped regions were defined by dopant implantation using a photo resist mask. We used a finger-like design as implantation masks to enable one contact area for each p-doped and each n-doped region (Fig. 1). This contacting approach differs from the standard GePD offered in the IHP ePIC technology. We analyzed I-V characteristics in dependence of detector design and contacting scheme (Fig. 2). In addition, process adjustments for the optimization of the germanium quality were investigated to reduce dark currents and to improve optical responsivities (Fig.3).Titanium nitride (TiN) is very promising metallic alloy with respect to thickness homogeneity and low surface roughness. Therefore we used titanium nitride which was deposited by a sputtering process to develop plasmonic active NHA layers. Various process development runs were done to evaluate the NHA performance. Ellipsometry and atomic force microscope measurements were performed to characterize the quality of the TiN layer (Fig.4). Figure 1

Application of Magnonic Crystals in Magnetic Bead Detection.

This paper aims at studying a sensor concept for possible integration in magnetic field-based lab-on-chip devices that exploit ferromagnetic resonance (FMR) phenomena in magnonic crystals. The focus is on 2D magnetic antidot arrays, i.e., magnetic thin films with periodic non-magnetic inclusions (holes), recently proposed as magnetic field sensor elements operating in the gigahertz (GHz) range. The sensing mechanism is here demonstrated for magnetic nano/microbeads adsorbed on the surface of permalloy (Ni80Fe20) antidot arrays with a rhomboid lattice structure and variable hole size. Through extensive micromagnetic modelling analysis, it is shown that the antidot arrays can be used as both bead traps and high-sensitivity detectors, with performance that can be tuned as a function of bead size and magnetic moment. A key parameter for the detection mechanism is the antidot array hole size, which affects the FMR frequency shifts associated with the interaction between the magnetization configuration in the nanostructured film and the bead stray field. Possible applications of the proposed device concept include magnetic immunoassays, using magnetic nano/microbeads as probes for biomarker detection, and biomaterial manipulation.

Integration of Screen Printed Piezoelectric Sensors for Force Impact Sensing in Smart Multifunctional Glass Applications

Screen printed piezoelectric polyvinylidene fluoride–trifluoro ethylene (PVDF–TrFE)‐based sensors laminated between glass panes in the temperature range 80–110 °C are presented. No degradation of the piezoelectric signals is observed for the sensors laminated at 110 °C, despite approaching the Curie temperature of the piezoelectric material. The piezoelectric sensors, here monitoring force impact in smart glass applications, are characterized by using a calibrated impact hammer system and standardized impact situations. Stand‐alone piezoelectric sensors and piezoelectric sensors integrated on poly(methyl methacrylate) are also evaluated. The piezoelectric constants obtained from the measurements of the nonintegrated piezoelectric sensors are in good agreement with the literature. The piezoelectric sensor response is measured by using either physical electrical contacts between the piezoelectric sensors and the readout electronics, or wirelessly via both noncontact capacitive coupling and Bluetooth low‐energy radio link. The developed sensor concept is finally demonstrated in smart window prototypes, in which integrated piezoelectric sensors are used to detect break‐in attempts. Additionally, each prototype includes an electrochromic film to control the light transmittance of the window, a screen printed electrochromic display for status indications and wireless communication with an external server, and a holistic approach of hybrid printed electronic systems targeting smart multifunctional glass applications.

Relationship between Tennis Sports Ability Consumption and Sports Characteristics Based on the Fusion Sensor Internet of Things

In recent years, under the promotion of social informatization and knowledge economy, sports undertakings have accepted and introduced information technology. It has begun to move forward on the road of sports informatization. The purpose of this paper is to study the relationship between the consumption of tennis exercise ability and movement characteristics of the fusion sensor Internet of Things and introduce the related concepts of sensors and the Internet of Things, as well as the related meanings of tennis exercise ability consumption and movement characteristics. The development of real-time sports data monitoring network has become the core of informatization. It first extracts information from a large amount of data that is helpful for making scientific management decisions for athletes and then formulates scientific management decisions for sports training. Finally, the goal of improving the technical and tactical level of athletes is achieved through various intelligent equipment or manual control measures. A survey was conducted on eight boys who like tennis, and the results showed that when r = 0.34, the midfielder draws and blocks the ball and was weakly related to the energy in the recovery period; r &lt; 0.3 midfield jump kill; total energy consumption during exercise and energy consumption in recovery period were almost irrelevant. The backcourt smash r = 0.533, indicating that the backcourt smash was moderately positively correlated with the energy consumption during the recovery period; the backcourt smash r = 0.826, indicating that the backcourt smash was highly positively correlated with the energy consumption during the recovery period.

Versatile selective absorption-based optical fiber toward epinephrine detection

A versatile lossy mode resonance (LMR) sensor is developed for Epinephrine monitoring based on the state-of-the-art molecular imprinting technique over an optical fiber. The optical absorption concept of the LMR-based sensor is proven by incorporating an amino silane-functionalized graphene oxide (SiO2-NH2@GO) as an adhesive layer for grafting Epinephrine imprinting polydopamine (Ep-IPDA) as a sensing layer onto the optical fiber curved surface. The accurate structural and morphological characterization confirmed the rough crystalline and spherical particles for Ep-IPDA and SiO2-NH2-GO onto optical fiber curved surface, while spectroscopic analysis confirms the formation of imprinting polymer and desirable absorbance characteristics. The optimized probe exhibits an excellent performance with the maximum sensitivity within two intervals of 0.3–1 µM and 1–90 µM along with the linearity coefficient of R2 = 0.99 possessing a low limit of detection of 0.07 µM. Additionally, this sensor selectively detects Ep in the presence of other species and showed good recovery in human urine and injection samples. This work opens a new avenue for developing bio-inspired LMR-based optical fiber biosensors and could be further extended to detect other catecholamine neurotransmitters.

Flexible unimodal strain sensors for human motion detection and differentiation

Multiple strain sensors are required to identify individual forces/stresses on human joints and recognize how they work together in order to determine the motion’s direction and trajectory. However, current sensors cannot detect and differentiate the individual forces/stresses and their contributions to the motion from the sensors’ electrical signals. To address this critical issue, we propose a concept of unimodal tension, bend, shear, and twist strain sensors with piezoelectric poly L-lactic acid films. We then construct an integrated unimodal sensor (i-US) using the unimodal sensors and prove that the i-US can detect and differentiate individual strain modes, such as tensioning, bending, shearing, and twisting in complex motion. To demonstrate the potential impact of unimodal sensors, we design a sleeve and a glove with the i-US that can capture wrist motions and finger movements. Therefore, we expect unimodal strain sensors to provide a turning point in developing motion recognition and control systems.