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Item type:Publication, Access status: with files , Powering mobile sensor nodes in fluidized beds: A non-invasive RF energy harvesting proof-of-concept(American Chemical Society (ACS), 2026-10-16); ; ; ; Real-time monitoring within industrial processing vessels is essential for advancing process analytical technology. Flow-following sensors represent an ideal approach for delivering continuous, in-line data from the process stream. However, deploying these mobile sensors is constrained by the physical barriers of sealed metallic vessels and harsh, battery-hostile environments. To overcome these limitations, a non-invasive, retrofittable wireless power transfer system is presented. The metallic vessel is structurally repurposed into a 5.23 GHz multi-mode microwave cavity resonator by coupling microwave energy through existing standard flanges. Electromagnetic simulations validate that this method generates continuous energy coverage throughout dynamic flow zones, demonstrated using a fluidized bed granulator as an application example. To harness this energy, an omnidirectional antenna and a compact RF-to-DC rectifier prototype were developed. By enabling the continuous operation of autonomous, battery-free mobile sensor nodes, this framework provides a practical, scalable foundation for high-density spatial analytics and data-driven industrial optimization.Publicationtype: Journal Article18 9 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Reconstruction-free EIT for injection-pattern classification and superficial gas velocity regression as proxies for local gas holdup in bubble columns(American Chemical Society (ACS), 2026-09-10); ; ; ; Electrical impedance tomography (EIT) as a noninvasive tomographic technique is increasingly applied to multiphase reactor monitoring; however, conventional image reconstruction is ill-posed and regularization-dependent and may be redundant in applications where the primary objective is operating-state identification rather than explicit spatial conductivity field reconstruction. Here, we present a reconstruction-free, measurement-domain framework for bubble-column monitoring that maps raw complex boundary impedance data directly to two reactor-relevant inference tasks: (i) gas injection pattern classification and (ii) superficial gas velocities regression. Together, these two quantities ─ the spatial injection distribution and the total volumetric flow ─ constitute the primary process-state information from which gas holdup can subsequently be inferred and are therefore reported as proxies for local gas holdup monitoring. Experiments were conducted in an acrylic bubble column (600 mm height, 104 mm inner diameter) equipped with a 256-electrode array distributed over eight axial rings and operated at four excitation frequencies (1 kHz-1 MHz). Experiments covered gas flow rates between 1.0 and 6.5 L min–1 (Ug = 1.96 → 12.75 mm s–1), within which near-perfect gas injection pattern classification was achieved with accuracies of 93–100% for excitation frequencies between 1 and 100 kHz using the full 256-electrode configuration. For quantitative superficial gas velocity estimation, increasing calibration density along Ug reduced the mean absolute error from 0.388 to 0.105 L min–1 (MAE[Ug] = 0.76 → 0.205 mm s–1, i.e. 7.0% → 1.9% of the operating range) for localized injection and from 0.298 to 0.157 L min–1 (MAE[Ug] = 0.585 → 0.307 mm s–1, i.e. 5.4% → 2.8% of the operating range) for distributed injection conditions. These results demonstrate that direct inference from raw EIT boundary measurements enables accurate, real-time monitoring of bubble-column operation without tomographic reconstruction and provide quantitative guidance on excitation frequency selection, axial sensing placement, and calibration resolution.Publicationtype: Journal Article31 27 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Aerographite vs Graphite: Investigating the role of electrode architecture in H2-mediated electroautotrophic biofilms(American Chemical Society (ACS), 2026-08-07); ; ; ; Oxic microbial electrosynthesis using aerobic hydrogenotrophic bacteria requires productive cathodic biofilm formation, yet reactive oxygen species (ROS) generated at the electrode surface present a critical barrier to initial colonization. This study investigates biofilm development by Cupriavidus necator H16 on Aerographite, an ultralow-density carbon foam (3–12 mg cm–3, porosity > 99%) with a hierarchical tetrapodal pore network, as a cathode material in microfluidic bioelectrochemical systems and compares it to graphite (a composite material consisting of graphite and polypropylene (PPG86)). A biphasic cultivation strategy, in which heterotrophic biofilm establishment preceded a switch to electroautotrophic conditions at −45.45 μA cm–2, successfully overcame the ROS barrier on both electrode materials. Noninvasive optical coherence tomography revealed a final biovolume of 0.086 mm3 mm–2 on graphite after 14 days, representing the first continuous kinetic characterization of C. necator cathode biofilm formation under defined flow conditions. Despite lower absolute biovolume per projected area, Aerographite supported higher biomass per unit electrode mass, reflecting its 585-fold higher mass-specific electroactive surface area relative to graphite. Scanning electron microscopy confirmed C. necator colonization of internal pore regions up to 500 μm below the electrode surface under laminar flow-over conditions. The macropore dimensions substantially exceed documented self-limiting biofilm thicknesses, indicating that pore occlusion is unlikely even at full biofilm development, and positioning Aerographite as a structurally enabling electrode material for smart, scalable, flow-through CO2 valorization systems.Publicationtype: Journal Article70 25 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , A cost-efficient electrical impedance tomography system for adaptive process analytics(American Chemical Society (ACS), 2026-08-02); ; ; ; Electrical impedance tomography (EIT) has significant potential as a noninvasive tool for spatially resolved process monitoring, yet most reported systems remain laboratory prototypes and are rarely suitable for integration into chemical engineering environments. We present a fully embedded, low-cost EIT platform designed as a deployable tomographic sensor for in situ monitoring of reactive media in laboratory-scale reactors. The platform can be realized for approximately $442 in prototype quantities and below $310 in small-batch production. The system enables spatially resolved conductivity mapping with 32 measurement channels and is designed for straightforward integration into laboratory and reactor environments. Its compact USB-powered hardware is complemented by microcontroller firmware in C and an object-oriented Python interface for experiment control and data analysis. On-board impedance calculation allows stand-alone operation and supports real-time monitoring of dynamic conductive processes. Hardware characterization includes measurements of total harmonic distortion plus noise for signal excitation and voltage measurement with mean values up to 0.0651%, a signal frequency of 105 kHz and optimized analogue amplification across all gain settings, a variable analogue filter gain ranging from −1.35 to 34.81 dB, and characterization of the current source at excitation currents of 100 and 350 μA. Additionally, the system’s performance is validated for the adjacent and opposed pair pattern, achieving a mean signal-to-noise ratio of up to 76.59 dB. The imaging performance is quantified on circular phantoms in terms of position error, spatial resolution, and detection limit, and the long-term stability is verified over a 20-h measurement with a relative drift below 0.03%. The system achieves frame rates of 7.36 to 13.18 fps depending on the measurement pattern. The system is validated in a chemically relevant scenario by monitoring the dissolution of 5 mol L–1 H2SO4(aq). The resulting spatial conductivity maps resolve transient concentration gradients associated with proton activity, illustrating the potential of the platform for the detection of local process states in adaptive reactor environments. Together, the characterized hardware performance and validation under chemically relevant conditions establish the platform as a scalable in situ imaging sensor suitable for integration into adaptive, data-driven reactor systems.Publicationtype: Journal Article28 29 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Towards simultaneous haptic experience for large audiences(Springer, 2026-07-29); ; ; ; While haptic feedback is a well-established tool for enhancing user engagement in gaming and cinema, its application in large-scale live events has been limited by the scalability and latency constraints of standard wireless protocols. For a truly immersive user experience, a solution must provide synchronized feedback to a mass audience with a perceptual delay of less than 20 ms. This paper presents a novel handheld device that delivers 6-Degrees of Freedom (DOF) haptic feedback and overcomes these challenges using analog Frequency Modulation (FM) broadcasting. The system utilizes a hybrid signal architecture, transmitting a continuous analog haptic waveform on one stereo channel and metadata for actuator control on the other. This approach guarantees scalability and low latency between all receiving devices, ensuring an enhanced user experience. A functional prototype was constructed and tested, verifying the feasibility of the proposed FM-based architecture. This research validates a scalable and low-latency solution for haptic experiences in large audiences, opening up new possibilities for artistic performances.Publicationtype: Book Part54 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , A visuo-haptic teleoperation platform for demonstration-based programming of force-sensitive robotic tasksIndustrial processes such as grinding, polishing, and precision assembly demand accurate force regulation and dexterous control. These operations are often repetitive and ergonomically challenging and, in some cases, can pose safety risks to human operators. This paper presents a teleoperation platform for Human–Robot Interaction (HRI) in force-sensitive robotic tasks, incorporating autonomous playback to support intuitive demonstration-based robot programming without complex manual coding. The proposed platform combines virtual reality (VR), optical tracking, and a vibrotactile operator tool within a ROS 2-based control architecture that interfaces with a UR10e industrial robot. A simulated Grinding task was utilized as a proof of concept. The VR environment offers a digital twin of the workspace, live video feedback, and scalable interaction with the workpiece for fine manipulation. Tool odometry generates velocity control commands for intuitive six Degree of Freedom (DoF) motion, while force feedback is conveyed through vibrotactile patterns and a color-coded visual overlay. Experimental validation demonstrated an end-to-end latency below 15 ms and positional errors under 5 mm. Repeatability tests yielded trajectory correlation coefficients (CC) above 0.8. A user study involving 17 participants was conducted to evaluate usability and overall user experience. The results showed high ratings for intuitiveness and system responsiveness, indicating that the proposed platform provides an effective and user-friendly framework for demonstration capture and autonomous replay of force-sensitive robotic operations.Publicationtype: Journal Article17 5 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Unbiased automated optimization of ship energy systemsShipping is highly efficient yet a significant greenhouse gas emitter. Achieving the IMO's 2050 carbon-neutrality target demands exceptionally efficient new vessel designs. However, ship design is complex due to the vast number of interacting options–e.g. hybrid electric architectures, renewable integration, sector coupling, and energy storage. Energy system design remains a largely manual, iterative process based on prior experience, often overlooking unconventional concepts. The Maritime Energy System Optimizer (MESO) addresses this gap. MESO is a modular Python platform optimizing the architecture, dimensioning, and operation of sector-coupled ship energy systems via a genetic algorithm. Fitness is evaluated through operational, component, and volume costs, with operation optimization using the open energy modeling framework. Its novelty lies in unbiased architecture optimization over dynamic load profiles, reducing design iterations. MESO is demonstrated in two case studies–a cruise ship's multi-energy system and a container ship's auxiliary electrical system–identifying efficient, unconventional configurations.Publicationtype: Journal Article33 11 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Experiencing coupled resonance dynamics when designing with vibrotactile actuators(IEEE, 2026-06-20); ; ; ; Vibrotactile actuators are used in touchscreens to create tactile feedback and defined crispy surface dynamics. Being mounted on such plastic structures the resulting surface dynamics can differ substantially from what idle actuator specifications predict. This paper identifies the root cause as a coupled resonance interaction between the actuator’s internal spring-mass-damper-system and the structural modes of the systems, and demonstrates that this interaction is very predictable from two standard measurements performed on the actuator alone. As a representative setting five rectangular polycarbonate plates of varying thickness are studied under three conditions: bare plate, bare plate with mounted actuator as a bare mass, and actuator with free moving mass. Laser Doppler vibrometer measurements show that when the plate’s natural frequency approaches the actuator’s internal resonance, the free actuator acts as a dynamic vibration absorber (DVA), splitting the structural resonance and introducing a pronounced anti-resonance. A Rayleigh-Ritz plate model coupled to a lumped-parameter actuator model parameterised exclusively by idle and blocked test measurements predicts all three response conditions without any fitting to plate data. The results establish internal mechanical impedance as the missing design parameter in vibrotactile system integration, and motivate a standardised two-test characterisation methodology applicable across many actuator types.Publicationtype: Conference Paper31 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Architectures of alteration: Designing and integrating hybrid kinetic robotic systems and light choreography in eternal dawn(2026-05-10); ; ; ; Contemporary performance increasingly relies on kinetic, robotic, and responsive environments that demand tightly integrated engineering systems capable of acting as expressive agents. Developing such hybrid systems contributes to new modes of staging, embodiment, and dramaturgy, offering artists tools for creating dynamic environments that extend beyond the limitations of human gesture alone. This paper presents the design and integration of two hybrid kinetic systems developed for the performance Eternal Dawn: a ceiling-mounted robotic arm and a motor-matrix architecture controlling suspended rectangular light frames. The robotic arm operates as a supervisory and interactive entity, shifting from analytical scanning to aggressive pendulum-like motion to intimate duet-like encounters. The motor-matrix system dynamically reconfigures the spatial geometry of the laboratory, synchronizing kinetic light choreography with sound and movement to construct adaptive architectural states. Synchronization with musical structures is achieved using Open Sound Control (OSC) messages ensuring accurate temporal coordination. The motors are controlled via a programmable logic controller (PLC) and a dedicated human–machine interface (HMI) managing motion parameters, sequencing, and safety functions. The proposed systems proved effective as expressive kinetic agents, demonstrating a versatile platform for integrating robotic motion and dynamic light architectures into similarly experimental performance setting.Publicationtype: Conference Paper28 10 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Impedance spectroscopy for multi-state analysis of dissolvable powders: determining layer thickness and moisture content(Elsevier, 2026-03-27); ; ; ; This study presents a novel methodology for applying Electrical Impedance Spectroscopy to analyze the electrical properties of dissolvable powders, when applied as a coating layer to quantify their thickness and moisture content. To address challenges posed by undefined geometries, powders were dissolved and applied as coatings on custom-designed Printed Circuit Board electrodes. Using sodium benzoate as a model material, the drying process was monitored in off-line measurements, revealing distinct transitions in electrical properties. Impedance and phase angle measurements effectively tracked moisture reduction during drying, while coating thickness and solution concentration also influenced conductivity. The findings demonstrate the potential of this approach for industrial applications, such as fluidized bed spray granulation, by enabling real-time monitoring of drying states.Publicationtype: Journal Article66 132