Mario Kupnik

Mario Kupnik
Technische Universität Darmstadt | TU · Department of Electrical Engineering and Information Technology

Prof. Dr. mont.

About

272
Publications
68,392
Reads
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3,344
Citations
Citations since 2016
113 Research Items
1847 Citations
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
Additional affiliations
March 2011 - December 2014
Brandenburg University of Technology Cottbus - Senftenberg
Position
  • Professor (Full)

Publications

Publications (272)
Article
Full-text available
As a novel stimulus, we use high-frequency ultrasonic waves to provide the required energy for breaking hydrogen bonds between Poly(N-isopropylacrylamide) (PNIPAM) and water molecules while the solution temperature is maintained below the volume phase transition temperature (VPTT = 32 °C). Ultrasonic waves propagate through the solution and their e...
Article
Laser-based powder bed fusion as an additive manufacturing process allows the integration of sensors at any location within the manufactured part. This allows for manufacturing smart parts that can be integrated into complex structures for monitoring applications, as they can perform in-situ measurements. Especially, monitoring of force and torque...
Article
Full-text available
Capacitive micromachined ultrasonic transducers (CMUTs) represent an accepted technology for ultrasonic transducers, while high bias voltage requirements and limited output pressure still need to be addressed. In this paper, we present a design for ultra-low-voltage operation with enhanced output pressure. Low voltages allow for good integrability...
Data
A rotating view of the CAD-Data of the Experimental Setup in "Multipath Flow Metering of High-Velocity Gas Using Ultrasonic Phased-Arrays"
Article
Full-text available
Sparse spiral phased arrays are advantageous for many emerging air-coupled ultrasonic applications, since grating lobes are prevented without being constrained to the half-wavelength element spacing requirement of well-known dense arrays. As a result, the limitation on the maximum transducer diameter is omitted and the aperture can be enlarged for...
Article
Full-text available
In this work we combine a multipath ultrasonic gas flow meter (UFM) with an ultrasonic air-coupled phased-array. This allows complementing the advantages of a multipath UFM, i.e. higher accuracy and more robustness to irregular flow, with the extended velocity measuring range due to sound drift compensation via a phased-array. We created a 3D-print...
Conference Paper
Sensor-integrating machine elements (SiME) are essential enablers for digitization in the industry. There are major challenges in the development of SiME as an interdisciplinary mechatronic system, requiring methodical support. In this work, we address these challenges and aim to provide methods and tools by analyzing the state-of-the-art and ten o...
Article
Waveguides allow grating lobe free beamforming for air-coupled ultrasonic phased-arrays by reducing the effective inter-element spacing to half wavelength. Since the sound waves propagate through the waveguide ducts, additional time delays are introduced. In this work, we present analytical, numerical, and experimental methods to estimate these tim...
Conference Paper
Bite force is an important characteristic of the masticatory systems functional state. Especially force asymmetries are potential indicators for malfunctions such as temporo-mandibular disorders or dysgnathia. By measuring bilaterally, i.e. simultaneously on the left and right side, it is possible to quantify asymmetries. Currently, there is a lack...
Conference Paper
Full-text available
Ferroelectrets are piezoelectric polymers, typically cellular polymer foams that exhibit a large piezoelectric response. In this work, we present a biodegradable 3D printed ferroelectret using Fused Deposition Modeling (FDM). Even though the charging process of the ferroelectret is conducted at room temperature, the printed PLA exhibits good charge...
Article
Full-text available
Piezoelectrets are artificial ferroelectrics that are produced from non-polar air-filled porous polymers by symmetry breaking through high-voltage-induced Paschen breakdown in air. A new strategy for three-layer polymer sandwiches is introduced by separating the electrical from the mechanical response. A 3D-printed grid of periodically spaced therm...
Conference Paper
Full-text available
Ferroelectrets are typical cellular polymer foams that exhibit high flexibility and an excellent matching to air. Recently, biodegradable cellular polylactic acid (PLA) ferroelectrets have been introduced, exhibiting a large longitudinal piezoelectric coefficient. In this work, we present a combination of a PLA film and a printed PLA backplate usin...
Article
Full-text available
Vibrational energy harvesters of air-spaced cantilever design, utilizing ferroelectrets as the electroactive element, are a very recent concept. Such systems, based on the d 31 piezoelectric effect are further studied with harvesters of improved design, partially implemented by additive manufacturing. The focus of the present work is on the depende...
Article
Ultrasound propagation in liquids is highly influenced by its attenuation due to viscous damping. The dissipated energy will be partially absorbed by the liquid due to its dynamic viscosity as well as its bulk viscosity. The former results in the generation of a flow that is called acoustic streaming, and the latter is associated with the vibration...
Conference Paper
Um den Menschen bedarfsgerecht und ergonomisch unterstützen zu können, müssen Assistenzsysteme die Bewegungen und Bewegungsabsichten des Nutzers frühzeitig erkennen. Die Individualität der menschlichen Bewegung ist dabei eine besondere Herausforderung. Dieser Beitrag zeigt, dass maschinelles Lernen geeignet ist, um aus den Daten ausgewählter, am Kö...
Chapter
We present a disruptive method for manufacturing structure-integrated force sensors based on the LPBF process by inserting a strain sensing steel plate in the additive manufacturing process of the deformation element. In order to investigate the strain transmission from the printed part to the integrated steel plate, we built two prototypes which d...
Conference Paper
We present a 15 N nominal force sensor, manufactured with a disruptive method based on laser-based powder-bed-fusion. This additive manufacturing process enables the application-specific realization of a deformation element for a structural integrated sensor for condition monitoring applications. Manufacturing of the deformation element is done by...
Article
Full-text available
People with physical disabilities in their upper extremities face serious issues in using classical input devices due to lacking movement possibilities and precision. This article suggests an alternative input concept and presents corresponding input devices. The proposed interface combines an inertial measurement unit and force sensing resistors,...
Article
Fluorinated polyethylene propylene (FEP) ferroelectrets with an air-filled parallel-tunnel structure and regularly distributed bipolar space charges can stimulate integration of ferroelectrets in transducers due to their unique piezoelectric and mechanical properties. Such FEP ferroelectret films exhibit not only large longitudinal piezoelectric ac...
Article
The new internet standard 5G offers new possibilities to combine and connect different platforms like artificial intelligence (AI) and the internet of things (IoT) which will influence almost all aspects of people's lives. The connectivity of all these things will revolutionize the way information will be transferred and distributed. In 2025 the am...
Conference Paper
Air-coupled ultrasonic sonar systems are a valuable complement to lidar sensors for safe navigation of autonomous vehicles, especially in environments with optically transparent and reflective surfaces. Consequently, sonar systems based on phased arrays and beamforming are a promising compact solution, providing precise and unambiguous 3D localizat...
Conference Paper
Determining the liquid level in containers is a challenging task in many industries, as there are different kinds of containers and liquids. The approach for measuring the liquid fill level presented in this paper comprises a low-voltage capacitive micromachined ultrasonic transducer (CMUT). We use a premolded package, providing sufficient acoustic...
Article
Full-text available
Polymers with electrically charged internal air cavities (ferroelectrets) reveal a pronounced piezoelectric response and are regarded as soft electroactive multi-functional materials. This work presents preliminary results on the preparation and piezoelectric effect of ferroelectrets based on the polylactic acid (PLA) polymer. A distinctive feature...
Conference Paper
Spiral-shaped phased arrays are widely used for sound source localization and are trending in other fields, e.g. 3D medical ultrasound imaging. The non-uniform element geometry allows grating lobe free beamforming without an inter-element spacing of half wavelength. We demonstrate the 3D imaging capabilities of an air-coupled ultrasonic 40-kHz phas...
Chapter
Full-text available
We present a wearable vibrotactile feedback device consisting of four linear resonant actuators (LRAs) that are able to generate virtual stimuli, known as phantom tactile sensation, for human-robot interaction. Using an energy model, we can control the location and intensity of the virtual stimuli independently. The device consists of mostly 3D-pri...
Conference Paper
Schlieren photography is widely used for visualiza-tion of acoustic or shock waves, e.g. in ballistics and aerodynamics. Due to the low molar refractivity of air the visualization of acoustic waves requires sensitive equipment or high sound pressure levels. We present a Schlieren system utilized in a non-destructive test setup, that is capable to v...
Article
We present an air-coupled ultrasonic imaging system based on a 40 kHz 8×8 phased-array for three-dimensional real-time localization of multiple objects in the far-field. By attaching a waveguide to the array, the effective inter-element spacing is reduced to half wavelength. This enables grating lobe free transmit and receive beamforming with a uni...
Article
Full-text available
We present a vibrational energy harvester with fluorinated ethylene propylene (FEP)-ferroelectrets working in d31 mode. The ferroelectret film consists of two FEP films, fused together to form a parallel tunnel structure with well-defined air gaps. Its dynamic piezoelectric g31 coefficient is 0.7 V m N−1. The energy-harvesting device is an air-spac...
Article
Advanced acoustic levitation devices featuring flexible, lightweight, wide bandwidth, and film-like transducers based on ferroelectrets are designed and fabricated for sophisticated manipulation of particles in a simple way. Owing to the unique properties of ferroelectret films, such as high piezoelectric activity, very small acoustic impedance, a...
Article
Full-text available
Despite limited scientific evidence, there is an increasing interest in soft robotic gloves to optimize hand- and finger-related functional abilities following a neurological event. This review maps evidence on the effects and effectiveness of soft robotic gloves for hand rehabilitation and, whenever possible, patients’ satisfaction. A systematized...
Article
Advanced acoustic levitation devices featuring flexible, lightweight, wide bandwidth, and film-like transducers based on ferroelectrets are designed and fabricated for sophisticated manipulation of particles in a simple way. Owing to the unique properties of ferroelectret films, such as high piezoelectric activity, very small acoustic impedance, a...
Article
Full-text available
Energy harvesting from vibrations provides power to low‐energy consuming electronics for stand‐alone and wearable devices as well as for wireless and remote sensing. In this contribution, compact tubular ferroelectret energy harvesters utilizing a single‐tube design are presented. Such single‐tube harvesters can be fabricated from commercially avai...
Conference Paper
We present a simulation of an ultrasonic transducer element with piezoelectric and electrostatic transduction combined and with two bending plates. It combines the high SPL of a piezoelectric transducer with the tunable resonance frequency of a CMUT due to spring softening effect. In this work, we compare two state-of-the-art transducers with our a...
Conference Paper
Full-text available
We present a 10 N nominal needle tip force sensor based on silicon-based semiconductor strain gauges that can be used in brachytherapy or biopsies. As deformation body the guiding rod of such a surgical needle with a diameter of 1.2 mm is used. In a thinned area, near the tip of the needle, the strain gauge, as sensing element, is applied with a fl...
Conference Paper
Full-text available
For quality control and functionality testing, Contact Normal Forces F N need to be measured in multi contact point connectors like MCON 8 with the least mating cycles possible. This article is about the design and the characterization of a 4-channel gage. Each channel gage consists of a metal transducer with a metal foil strain gage. The forces ra...
Conference Paper
This paper derives an analytical model of the electrostatic transduction of a capacitive micromachined ultrasonic transducer (CMUT) with mechanically coupled plate actuators. The mass of the coupling geometry significantly affects the dynamic deflection shape of the plate actuators. As the electrostatic transduction of a CMUT depends on the distanc...
Conference Paper
Full-text available
We present a three-dimensional far-field imaging method using an air-coupled 40 kHz 8×8 ultrasound phased-array. A waveguide is attached to the array which reduces the aperture to 35 mm×35 mm and the inter-element spacing to λ /2 for grating lobe free beamforming. Using transmit beamforming, a pulse echo detection is performed sequentially for each...
Conference Paper
Full-text available
Continuum robots are inspired by biological trunks, snakes and tentacles. Unlike conventional robot manipulators, there are no rigid structures or joints. Advantageous is the ease of miniaturization combined with high dexterity, since limiting components such as bearings or gears can be omitted. Most currently used actuation elements in continuum r...
Article
Full-text available
Piezoelectret films prepared by irradiated cross-linked polypropylene (IXPP) not only feature a large figure of merit ( d 33 · g 33 , FoM) and a nearly flat response of the sensitivity as a microphone (4 mV Pa ⁻¹ ) in the audio range, but also exhibit a good impedance match to air. Therefore, this material is appropriate for air-coupled sonic and u...
Article
Full-text available
In minimally invasive surgery, new flexible instruments enable safer and easier access to difficult-to-reach anatomical regions. However, their introduction into the clinical workflow requires robust replanning, because navigation errors during surgery render initially planned trajectories infeasible. Such replanning requires to regularly solve an...
Article
High sensitivity is an important requirement for air-coupled ultrasonic sensors applied to materials testing. With a lower acoustic impedance than any piezoelectric material, charged cellular polypropylene (PP) offers better matching to air with a similar piezoelectric coefficient. The piezoelectric properties of charged cellular PP originate from...
Conference Paper
Full-text available
Functional impairment of the hand, for example after a stroke, can be partially improved by intensive training. This is currently done by physiotherapy and the optimal intensity of hand rehabilitation programs is usually not reached due to a lack in human resources (high costs) and patients fatigue. In this work a cost-effective soft exosuit to sup...
Conference Paper
Full-text available
Zusammenfassung: Formgedächtnislegierungen (FGLen) werden bereits in verschiedensten Anwendungen in der Medizin eingesetzt. Hierzu zählen unter anderem medizinische Implantate, wie zum Beispiel Stents (Gefäßstützen) und orthodontische Drähte, die von der superelastischen Eigenschaft von Nickel-Titan Gebrauch machen. Darüber hinaus existiert jedoch...
Article
In this paper we present a structural analytical model for a capacitive micromachined ultrasonic transducer (CMUT), based on a sacrificial release fabrication process and comprised of electro-mechanical plate actuators transferring their motion to a coupling roof structure on top. The structure features a larger average displacement compared to con...
Conference Paper
Unforced choice tasks (i.e. tasks that allow a “don’t know”-response) are expected to reduce response uncertainty for test subjects, especially at low stimulus intensities. In this work, we present simulated and behavioral data for unforced choice tasks using standard staircase (2-down/1-up), and parametric (updated maximum likelihood; UML, and Bay...
Article
With the anticipation for a more connected world through the Internet of Things, there is still a strong demand for miniaturized chemical sensors. Here, we report on a miniaturized resonant chemical sensor based on a Capacitive Micromachined Ultrasonic Transducer (CMUT) with a low operating voltage suitable for portable gas sensor applications. Pre...
Chapter
We present a proof-of-concept for pseudohaptic feedback in gripping interactions. This paper includes a review about known applications of pseudohaptic feedback in virtual reality and teleoperation as well as the results of an identification experiment in a gripping task. In this experiment, 16 subjects identified five stimuli with different compli...
Article
This paper derives an analytical model of a capacitive pressure transducer based on equations for deflection and fundamental mode shape of a clamped circular plate. The derived model enables efficient large-signal electromechanical simulations and calculation of an equivalent circuit. The model shows good agreement with finite element analysis and...
Article
Zusammenfassung Die Bestimmung der Bewegungsintention stellt eine Herausforderung in der Mensch-Roboter-Kooperation dar, um einen sicher und intuitvive Bedienung zu ermöglichen. Hierzu werden zwei Messprinzipen zur Nutzerintentionserkennung mit einem Oberarm-Exoskelett untersucht. Für die Antriebsachsen wird ein strukturintegrierter Drehmomentsenso...
Article
Full-text available
This tutorial describes the necessary steps for designing and conducting a perception experiment in order to obtain design parameters for human–machine interactions. It is intended for engineers and product designers, which require design parameters not included in the current state of the art. Topics addressed are the preposition of hypotheses, th...
Conference Paper
Current methods to compare measurement series are based on the comparison of multiple measurement points or fit parameters. These approaches depend on the quality of the fit and are prone to type I error accumulation, when standard statistical tests are used for evaluation. In this work, we present an approach based on a two-sample Kolmogorov-Smirn...
Conference Paper
Needle insertion is a common medical task. Certain procedures such as brachytherapy, biopsies or punctures of pericardial effusions require the insertion of comparably thick needles (Ø 1 mm) into human tissue. A large risk of additional tissue damaging exists because of the needle size. Additionally, the needle compresses and displaces tissue adjac...
Conference Paper
Full-text available
We present a non-destructive measurement procedure to obtain material properties on parts manufactured using the Fused-Deposition-Modeling (FDM) method. This manufacturing method leads to an anisotropic structure within the part and possible degradation of the material itself due to high temperatures. Utilizing our measurement setup, we obtain the...
Conference Paper
Coded excitation techniques have been widely used in radar and sonar for improved resolution and noise performance. Whilst becoming more common in medical ultrasound, only few industrial applications have been reported. We present some results from work looking at air-coupled phased arrays aiming at improved air flow speed measurements. The high in...
Conference Paper
Full-text available
Highly sensitive air-coupled ultrasonic sensors are essential for various applications such as testing of composite materials. One of the major challenges for the development of air-coupled ultrasonic sensors is the impedance matching to air. With a lower acoustic impedance than the usual piezoelectric materials, charged cellular polypropylene film...