Alexander Frey

Alexander Frey
University of Applied Sciences Augsburg · Faculty of Electrical Engineering

Master of Arts, Dipl. Phys, Prof. Dr.-Ing.

About

86
Publications
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992
Citations

Publications

Publications (86)
Article
The field of electrostatics and electrophotography offers great potential for applying powder layers for powder bed-based additive manufacturing processes, such as powder bed fusion of metals using a laser beam (PBF-LB/M). The authors introduce a highly flexible powder layer forming process using the electrophotographic principle. The focus is on f...
Conference Paper
This work focuses on a low-cost fabrication process developed beyond cleanroom environment for realization of elastic microfluidic devices. The method based on thermoplastic deformation of biocompatible polymers allows a simultaneous integration of 3D-shaped electrodes to ensure precise dielectrophoretic separation processes in case of stretching o...
Conference Paper
Finite Element Method is used to model the voltage drop inside dielectrophoresis actuators. Frequency dependence is investigated for varying electrochemical conditions and actuator geometries. A hands-on equation to calculate the operation cut off frequency with respect to the electrode geometry is derived. Lumped element modeling is validated by v...
Conference Paper
Die vorliegende Arbeit führt in die Grundlagen des Skalierungsverhaltens von translatorischen Energiewandlern ein. Einleitend dazu werden kurz energieautarke Systeme vorgestellt, deren Energieversorgung mittels translatorischer Energiewandler erfolgen kann. Des Weiteren werden ein kurzer Abriss und eine systematische Methodik zu den Grundlagen des...
Article
Full-text available
Additive manufacturing gives new freedom to part design by enabling the manufacturing of complex structures. Mastering this degree of freedom poses challenges for product developers with experience from conventional manufacturing. In order to meet this challenge in a structured manner, a practical method is presented in which creative idea developm...
Conference Paper
https://www.comsol.com/paper/modelling-of-a-thermal-time-of-flight-sensor-for-low-rate-open-channel-flow-82401
Conference Paper
Full-text available
This work is related to Additive Manufacturing. The objective is to support the development of a novel particle application system based on electro-statics. Particles are to be arranged selectively in thin layers via Coulomb forces for the production of multi-material components. Experiments are conducted and the results used in two separate COMSOL...
Conference Paper
https://www.comsol.de/paper/eigenfrequency-app-for-university-laboratory-education-64321
Conference Paper
Full-text available
https://www.comsol.de/paper/modeling-of-substrate-plate-preheating-to-predict-efficiency-in-the-electron-bea-64291
Conference Paper
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https://www.comsol.de/paper/3d-printed-microfluidic-chip-system-for-dielectrophoretic-manipulation-of-colloi-62941
Conference Paper
https://www.comsol.de/paper/analysis-of-an-inductive-proximity-sensor-37911
Conference Paper
Full-text available
https://www.comsol.de/paper/analysis-of-geometrical-aspects-of-a-kelvin-probe-40251
Conference Paper
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In this work, COMSOL is used to extract electrical PMSM parameters required for a behavioral model. Using the COMSOL Rotating Machinery, Magnetic application mode enables efficient model setup. A procedure is described showing how the d-and q-axis motor inductances are obtained. In addition, the voltage constant related to the motional e.m.f. is de...
Article
Full-text available
This paper presents a novel non-resonant electromagnetic energy harvester for application in a remote car-key, to extend the lifetime of the battery or even to realize a fully energy autonomous, maintenance-free car-key product. Characteristic for a car-key are low frequency and large amplitude motions during normal daily operation. The basic idea...
Patent
Full-text available
A sensor arrangement for detecting particles potentially contained in an analyte is disclosed. The arrangement includes a substrate; at least one sensor electrode which is arranged on and/or in the substrate and on which scavenger molecules, which hybridize with particles that are potentially contained in an analyte and are to be detected, are immo...
Conference Paper
Full-text available
This paper presents a new approach to energy harvesting for use in sensor applications. It explores the possibility of using low frequency high power forces to generate energy. The subject is approached by showing the feasibility of an autonomous tire pressure monitoring system (TPMS). Any section of a car’s tire gets a periodic bump when with ever...
Article
Zusammenfassung In der vorliegenden Arbeit wird ein kurzer Abriss zur energieautarken Sensorik im Automobil gegeben. Hierzu wird auf die Vielfalt der Sensoren im heutigen Kraftfahrzeug eingegangen und eine Motivation bezüglich der Substitution hin zu energieautarken Sensoren aufgezeigt. Des Weiteren werden potentielle Nutzenergien und die Möglichke...
Article
Zusammenfassung Der Systementwurf eines piezoelektrischen Versorgungsmoduls für ein energieautarkes Reifendruck-Kontrollsystems (RDKS) wird beschrieben. Hierfür werden der Generatorentwurf unter Einbeziehung des piezoelektrischen Materialsystems sowie die Auslegung der spezifischen Schnittstellenschaltung betrachtet. Die vorgestellte, auf einer ana...
Conference Paper
Full-text available
In this paper, two different solutions for efficient solar powered sensor networks are presented and compared. Some fundamental considerations on the interaction of the solar cell, the storage capacitors, the DC/DC converters and the wireless radio transmitter are reviewed. The challenges for implementing a direct DC/DC conversion for powering wire...
Article
This paper presents a fully autonomous, adaptive pulsed synchronous charge extractor (PSCE) circuit optimized for piezoelectric harvesters (PEHs) which have a wide output voltage range 1.3-20 V. The PSCE chip fabricated in a 0.35 μm CMOS process is supplied exclusively by the buffer capacitor where the harvested energy is stored in. Due to the low...
Conference Paper
Full-text available
This article presents the realization of a new, energy self-powered sensor node. The wireless node is supplied by 10μWatt of electrical power and is able to send three measured values in intervals of 80 seconds. The power supply is carried out with a MEMS-based piezoelectric vibration converter. A specially developed ASIC for this type of generator...
Conference Paper
This article presents the realization of a new energy self-powered sensor node. The wireless node is supplied by 10 μW of electrical power and is able to send three measured values in intervals of 80s. The power supply is carried out with a MEMS-based piezoelectric vibration converter. A specially developed ASIC for this type of generator takes ove...
Article
Full-text available
In this paper we consider a piezoelectric energy harvesting module for a tire based wireless sensor node application. A dedicated MEMS harvester operated with a non-resonant excitation scheme is proposed. In context with this novel operation scheme, dissipative damping mechanisms have to be taken into account for the MEMS design. In this work we in...
Conference Paper
This paper presents a fully autonomous, self- adjusting pulsed synchronous charge extractor chip optimized for piezoelectric harvesters with an output voltage from 3V to 18V. The chip which has been fabricated in a 0.35µm CMOS process is supplied exclusively by the buffer capacitor where the harvested energy is stored in. Due to the low power consu...
Article
The paper reports the system design of a piezoelectric energy harvesting module for a tire based wireless sensor node application. Impacts of material propertie, generator design and power management circuitry are considered. In context of a non-resonant generator excitation scheme, dissipative damping mechanisms are investigated. In particular air...
Article
In this paper a new approach of a shape-optimized piezoelectric MEMS generator for fluid-actuated energy scavenging is presented. Different energy scavenging scenarios are introduced. Depending on the specific load scenario optimum piezoelectric cantilever shapes are investigated. A point load at the free-end of a cantilever requires a triangular c...
Article
This paper reports the design of a piezoelectric energy harvesting module for a tire based wireless sensor node. System considerations comprise the generator design, material impact and the generator interface circuitry. A design procedure is presented, which allows identifying a geometry design space for the piezoelectric microgenerator consistent...
Article
In this paper a novel MEMS design of a piezoelectric generator for fluid-actuated energy conversion is presented. An exemplary energy scavenging scenarios is introduced. Moreover, the electro-mechanical properties of different piezoelectric thin films (PZT, AlN, ZnO) are introduced and compared to each other. Depending on the specific load scenario...
Conference Paper
This paper reports the optimum design, fabrication and characterization of a piezoelectric MEMS generator for fluid-actuated energy harvesting. Depending on the specific load scenario optimum beam shapes of piezoelectric cantilevers are investigated by theoretical estimations and related experiments. A point load at the free-end of a cantilever req...
Article
DNA sensor arrays integrated on CMOS chips allow fully electronic readout of biological information. Compared to state-of-the-art optical methods optical setups are not needed. Key features of fully electronic systems are robust and easy operation. These features enable applications in new fields and markets like diagnosis in doctors' offices, food...
Article
Full-text available
This paper reports the optimum design, fabrication and characterization of a piezoelectric MEMS generator for fluid-actuated energy harvesting. Depending on the specific load scenario optimum beam shapes of piezoelectric cantilevers are investigated by theoretical estimations and related experiments. A point load at the free-end of a cantilever req...
Article
Full-text available
In this paper we describe the system design of a piezoelectric MEMS energy harvesting module based on analytical modeling. The application example of a wireless sensor node for tire condition monitoring is considered. Key specifications which are taken into account are the power budget for the system operation, the system mass and the area consumpt...
Article
A rail-to-rail potentiostat circuit suitable for CMOS based electronic bio sensors is presented. The design approach enables robust operation far a large range of electrochemical conditions. Measurement results prove proper operation of the potentiostatic control circuitry.
Article
Full-text available
A circuit architecture is proposed, which enables an improved system startup for vibration based piezoelectric microgenerators. The innovative approach is based on an optimized synchronous rectifier design and a new trigger circuit. The new architecture is realized as an ASIC in 3.3 V, 0.35 μm CMOS technology. Simulations and experimental measureme...
Conference Paper
A fully integrated innovative micro system for biochemical analysis is presented. Direct electrical detection by means of an electrochemical method is used. In contrast to state-of-the-art optical methods, this allows for a simple cost-optimized realization of sensor systems with high sensitivity. The system integration is based on a standard CMOS...
Article
This paper reports on the design and analysis of a capacitive vibration-to-electrical energy converter. A theoretical design model of a parallel-plate electrostatic spring-mass-system is presented, based on state space equations. The charging of the parallel-plate capacitor takes place by utilizing materials with different work functions for the el...
Article
This paper reports on the design and analysis of a capacitive vibration-to-electrical energy converter. A theoretical design model of a parallel-plate electrostatic spring-mass-system is presented, based on state space equations. The charging of the parallel-plate capacitor takes place by utilizing materials with different work functions for the el...
Article
Full-text available
CMOS-based sensor array chips provide new and attractive features as compared to today's standard tools for medical, diagnostic, and biotechnical applications. Examples for molecule- and cell-based approaches and related circuit design issues are discussed.
Conference Paper
This paper reports on the design and analysis of a capacitive vibration-to-electrical energy converter. A theoretical design model of a parallel-plate electrostatic spring-mass-system is presented, based on state space equations. The charging of the parallel-plate capacitor takes place by utilizing materials with different work functions for the el...
Article
A kerf and tester compatible test structure is presented which allows fast and reliable evaluation of resistance and capacitance values of DRAM memory cells. The circuit is realized in a 70nm DRAM process, consumes an area of 795mum times 76mum, and requires six interconnect pads. Using standard electrical measurement equipment, the characterizatio...
Conference Paper
Full-text available
CMOS-based sensor array chips provide new and attractive features as compared to today's standard tools for medical, diagnostic, and biotechnical applications. Examples for molecule- and cell-based approaches and related circuit design issues are discussed.
Article
A CMOS chip-based approach is reviewed for fully electronic DNA detection. The electrochemical sensor principle used, CMOS integration of the required transducer materials, chip architecture and circuit design issues are discussed, respectively. Electrochemical and biological results obtained on the basis of medium density microarray sensor CMOS ch...
Article
Full-text available
A 16 × 8 sensor array chip for fully electronic DNA detection is presented. The sensor principle is based on an electrochemical redox cycling process. The chip is fabricated on the basis of an extended 0.5 μm CMOS process. Each sensor site of the array chip contains a complete A/D converter with a dynamic range of five decades. The 3σ-homogeneity o...
Conference Paper
An overview is given of CMOS-based sensor and actuator chips for in-vitro applications in the biotechnology area. We address the challenges and the potential of the combination of solid-state circuits with the wet world of bio molecules and living cells. Basic biological operating principles, market considerations, extended CMOS processing issues,...
Conference Paper
An overview is given of CMOS-based sensor- and actuator chips for in-vitro applications in the biotechnology area. We address the challenges and the potential of the combination of solid-state circuits with the wet world of bio molecules and living cells. Basic biological operating principles, market considerations, extended CMOS processing issues...
Conference Paper
Full-text available
A 16x8 CMOS sensor array for fully electronic DNA detection is presented. Each position contains a complete A/D converter with a dynamic range of five decades. The 3σ-homogeneity of the electrical response of the sensor array is better than 6% (10<sup>-21</sup>A to 10<sup>-7</sup>A). The 28.8mm<sup>2</sup> IC is fabricated in a 0.5μm 2M CMOS proces...