Friedemann Tonner - Academia.edu (original) (raw)

Uploads

Papers by Friedemann Tonner

Research paper thumbnail of Dispositif de détection irréversible du dépassement d'une température prédéterminée et un procédé de fabrication du dispositif

L'invention concerne un dispositif servant a detecter de maniere irreversible qu'une temp... more L'invention concerne un dispositif servant a detecter de maniere irreversible qu'une temperature predeterminee est depassee et un procede de fabrication du dispositif. Le dispositif comporte une couche de substrat (12), sur laquelle est appliquee une couche de matiere fusible (17) qui passe de l'etat solide a l'etat liquide lorsqu'un point de fusion de la couche de matiere (17) est depasse, et des particules (19) introduits dans la couche de matiere (17). La couche de substrat (14) est constituee d'une matiere poreuse qui absorbe au moins partiellement la couche de matiere (17) une fois que le point de fusion est depasse et les particules contenues (19) dans la couche de matiere (17) sont au moins partiellement separees par filtration a la surface (18) de la couche de substrat (12).

Research paper thumbnail of Electrochemical Synthesis Production methods of graphene and resulting material properties

Research paper thumbnail of Autonome quantenthermodynamische Maschinen

In dieser Arbeit werden bis in den Quantenlimes skalierbare thermodynamische Maschinen untersucht... more In dieser Arbeit werden bis in den Quantenlimes skalierbare thermodynamische Maschinen untersucht, die autonom arbeiten, d.h. ohne zeitabhangige (klassische) Kontrolle von ausen funktionsfahig sind. Inwieweit stost die Skalierung an fundamentale quantenmechanische Grenzen wie Dekoharenz? Das quantenmechanische Minimalmodell besteht aus einem einzelnen Spin (Zwei-Niveau-System), der an einen harmonischen Oszillator und an zwei thermische Bader unterschiedlicher Temperatur koppelt. Durch eine entsprechend gestaltete Lindbladgleichung kann dieses System als thermodynamische Maschine wirken, die Carnot-Zyklen aufweist. Der Badkontakt wird dabei vom Oszillatorzustand mit Hilfe hier vorgestellter so genannter Time-slot-Operatoren autonom gesteuert: Time-slot-Operatoren ermoglichen es, eine beliebige Kontrollfunktion auf Quantenebene zu implementieren. Selbst nahe des Quantenlimes kann fur das Minimalmodell der Warmekraftmaschine eine Verstarkung der koharenten Oszillatorbewegung nachgewie...

Research paper thumbnail of Fluidic Oscillations as Energy Source for Flow Sensors

Fluidic oscillations can be used as an energy source for self-sufficient sensors. We designed, si... more Fluidic oscillations can be used as an energy source for self-sufficient sensors. We designed, simulated and tested a fluidic oscillator based on the Coanda effect. It is able to work within media like air and water. Preliminary measurements show that our oscillator can harvest approximately 150µW of power by coupling a piezoelectric chamber to one of its channels. Future work will be focused on optimization of oscillators with the help of an automation tool in order to offer an integrated self-sufficient wireless sensor node.

Research paper thumbnail of Integration of CNT-based actuators for bio-medical applications — Example printed circuit board CNT actuator pipette

2014 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, 2014

In order to strengthen the position of CNT actuator technology and fasten the transfer of scienti... more In order to strengthen the position of CNT actuator technology and fasten the transfer of scientific results into application development and market introduction scientific institutes AIST Kansai and Fraunhofer IPA cooperated in the field of electroactive polymers. Automated dosing of small amounts of liquids normally involves quite large pipettes and motors for pipette actuation. Miniaturized pipettes can enable new areas, in which micro dosing is demanded and could be particularly beneficial in the field of medical or (bio-) chemical applications. The approach was the direct integration of a bending CNT actuator into a PCB design, which enables a frictionless induction of movement onto a liquid. The driving electronics control the actuator with a low voltage and can be placed on the same PCB. The result is a smooth, tailorable dispensation of liquid from the pipette with the ability to integrate the pipette into a fully automated system.

Research paper thumbnail of Konzept zur Inbetriebnahme eines Spannungswandlers Concept to commissioning a voltage converter

Research paper thumbnail of Energy supplying method for e.g. proximity sensor used for building automation, involves selecting frequency of base-high frequency-alternating current voltage so that carrier impedance is increased using skin effects and/or self induction

Research paper thumbnail of Theoretical versus experimental performance transfer analysis of multiple carbon nanotube actuator systems

Research paper thumbnail of Development and investigations on multiple carbon nanotube actuator systems for magnified performance and minimization of performance losses

Research paper thumbnail of Autonomous quantum thermodynamic machines

Physical review. E, Statistical, nonlinear, and soft matter physics, 2005

We investigate the dynamics of a quantum system consisting of a single spin coupled to an oscilla... more We investigate the dynamics of a quantum system consisting of a single spin coupled to an oscillator and sandwiched between two thermal baths at different temperatures. By means of an adequately designed Lindblad equation, it is shown that this device can function as a thermodynamic machine exhibiting Carnot-type cycles. For the present model, this means that when run as a heat engine, coherent motion of the oscillator is amplified. Contrary to the quantum computer, such a machine has a quantum as well as a classical limit. Away from the classical limit, it asymptotically approaches a stationary transport scenario.

Research paper thumbnail of Reduced Collective Description of Spin‐Ensembles

Quantum Information Processing, 2005

Research paper thumbnail of Electrochemical Exfoliation

Graphite, Graphene, and Their Polymer Nanocomposites, 2012

Research paper thumbnail of Experimental investigations on carbon nanotube actuators defining the operation point and its standard deviation

Electroactive Polymer Actuators and Devices (EAPAD) 2010, 2010

Carbon nanotube (CNT) actuators have been extensively investigated from the perspective of materi... more Carbon nanotube (CNT) actuators have been extensively investigated from the perspective of materials, their composition, and system construction as well as from three main performance features, which are displacement, force and velocity. However, up till now none of the CNT actuators have reached the stage of implementation into products. It is due to the fact that even though from the point of view of performance each property can reach satisfactory values, their combination is much more difficult, as they are not proportional. This relation of properties motivated the work to test and investigate currently available CNT-polymer actuators to define their operation point. Under this term one should understand a performance of actuator where displacement, force and velocity do not affect each other. In other words, any change in one of the properties will adversely affect at least one of the remaining ones. The measurements are performed in out-of-plane mode on 2 cm diameter samples in low frequency range (0.01-1 Hz) under application of low voltage (2 V). Measurement curves of three main actuator properties are plotted together against the frequency resulting in operation point as the intersection point of those curves. Additionally the deviations in actuator performance are assessed to reflect the actuators' reproducibility and their production process stability by means of standard deviation. Knowledge about the relation between actuator properties and the value of operation point will facilitate evaluation of the existing CNT actuator against its potential applications.

Research paper thumbnail of Quantum limit of the Carnot engine

Fortschritte der Physik, 2006

To what extent can the design principles of a macroscopic machine be down-scaled to the nanoscopi... more To what extent can the design principles of a macroscopic machine be down-scaled to the nanoscopic level? This question pertains to machine functions as diverse as information processing or energy conversion. Here we will be concerned with the class of Carnot engines. Our minimal model consists of a single spin coupled to an oscillator sandwiched between two thermal baths at

Research paper thumbnail of Dispositif de détection irréversible du dépassement d'une température prédéterminée et un procédé de fabrication du dispositif

L'invention concerne un dispositif servant a detecter de maniere irreversible qu'une temp... more L'invention concerne un dispositif servant a detecter de maniere irreversible qu'une temperature predeterminee est depassee et un procede de fabrication du dispositif. Le dispositif comporte une couche de substrat (12), sur laquelle est appliquee une couche de matiere fusible (17) qui passe de l'etat solide a l'etat liquide lorsqu'un point de fusion de la couche de matiere (17) est depasse, et des particules (19) introduits dans la couche de matiere (17). La couche de substrat (14) est constituee d'une matiere poreuse qui absorbe au moins partiellement la couche de matiere (17) une fois que le point de fusion est depasse et les particules contenues (19) dans la couche de matiere (17) sont au moins partiellement separees par filtration a la surface (18) de la couche de substrat (12).

Research paper thumbnail of Electrochemical Synthesis Production methods of graphene and resulting material properties

Research paper thumbnail of Autonome quantenthermodynamische Maschinen

In dieser Arbeit werden bis in den Quantenlimes skalierbare thermodynamische Maschinen untersucht... more In dieser Arbeit werden bis in den Quantenlimes skalierbare thermodynamische Maschinen untersucht, die autonom arbeiten, d.h. ohne zeitabhangige (klassische) Kontrolle von ausen funktionsfahig sind. Inwieweit stost die Skalierung an fundamentale quantenmechanische Grenzen wie Dekoharenz? Das quantenmechanische Minimalmodell besteht aus einem einzelnen Spin (Zwei-Niveau-System), der an einen harmonischen Oszillator und an zwei thermische Bader unterschiedlicher Temperatur koppelt. Durch eine entsprechend gestaltete Lindbladgleichung kann dieses System als thermodynamische Maschine wirken, die Carnot-Zyklen aufweist. Der Badkontakt wird dabei vom Oszillatorzustand mit Hilfe hier vorgestellter so genannter Time-slot-Operatoren autonom gesteuert: Time-slot-Operatoren ermoglichen es, eine beliebige Kontrollfunktion auf Quantenebene zu implementieren. Selbst nahe des Quantenlimes kann fur das Minimalmodell der Warmekraftmaschine eine Verstarkung der koharenten Oszillatorbewegung nachgewie...

Research paper thumbnail of Fluidic Oscillations as Energy Source for Flow Sensors

Fluidic oscillations can be used as an energy source for self-sufficient sensors. We designed, si... more Fluidic oscillations can be used as an energy source for self-sufficient sensors. We designed, simulated and tested a fluidic oscillator based on the Coanda effect. It is able to work within media like air and water. Preliminary measurements show that our oscillator can harvest approximately 150µW of power by coupling a piezoelectric chamber to one of its channels. Future work will be focused on optimization of oscillators with the help of an automation tool in order to offer an integrated self-sufficient wireless sensor node.

Research paper thumbnail of Integration of CNT-based actuators for bio-medical applications — Example printed circuit board CNT actuator pipette

2014 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, 2014

In order to strengthen the position of CNT actuator technology and fasten the transfer of scienti... more In order to strengthen the position of CNT actuator technology and fasten the transfer of scientific results into application development and market introduction scientific institutes AIST Kansai and Fraunhofer IPA cooperated in the field of electroactive polymers. Automated dosing of small amounts of liquids normally involves quite large pipettes and motors for pipette actuation. Miniaturized pipettes can enable new areas, in which micro dosing is demanded and could be particularly beneficial in the field of medical or (bio-) chemical applications. The approach was the direct integration of a bending CNT actuator into a PCB design, which enables a frictionless induction of movement onto a liquid. The driving electronics control the actuator with a low voltage and can be placed on the same PCB. The result is a smooth, tailorable dispensation of liquid from the pipette with the ability to integrate the pipette into a fully automated system.

Research paper thumbnail of Konzept zur Inbetriebnahme eines Spannungswandlers Concept to commissioning a voltage converter

Research paper thumbnail of Energy supplying method for e.g. proximity sensor used for building automation, involves selecting frequency of base-high frequency-alternating current voltage so that carrier impedance is increased using skin effects and/or self induction

Research paper thumbnail of Theoretical versus experimental performance transfer analysis of multiple carbon nanotube actuator systems

Research paper thumbnail of Development and investigations on multiple carbon nanotube actuator systems for magnified performance and minimization of performance losses

Research paper thumbnail of Autonomous quantum thermodynamic machines

Physical review. E, Statistical, nonlinear, and soft matter physics, 2005

We investigate the dynamics of a quantum system consisting of a single spin coupled to an oscilla... more We investigate the dynamics of a quantum system consisting of a single spin coupled to an oscillator and sandwiched between two thermal baths at different temperatures. By means of an adequately designed Lindblad equation, it is shown that this device can function as a thermodynamic machine exhibiting Carnot-type cycles. For the present model, this means that when run as a heat engine, coherent motion of the oscillator is amplified. Contrary to the quantum computer, such a machine has a quantum as well as a classical limit. Away from the classical limit, it asymptotically approaches a stationary transport scenario.

Research paper thumbnail of Reduced Collective Description of Spin‐Ensembles

Quantum Information Processing, 2005

Research paper thumbnail of Electrochemical Exfoliation

Graphite, Graphene, and Their Polymer Nanocomposites, 2012

Research paper thumbnail of Experimental investigations on carbon nanotube actuators defining the operation point and its standard deviation

Electroactive Polymer Actuators and Devices (EAPAD) 2010, 2010

Carbon nanotube (CNT) actuators have been extensively investigated from the perspective of materi... more Carbon nanotube (CNT) actuators have been extensively investigated from the perspective of materials, their composition, and system construction as well as from three main performance features, which are displacement, force and velocity. However, up till now none of the CNT actuators have reached the stage of implementation into products. It is due to the fact that even though from the point of view of performance each property can reach satisfactory values, their combination is much more difficult, as they are not proportional. This relation of properties motivated the work to test and investigate currently available CNT-polymer actuators to define their operation point. Under this term one should understand a performance of actuator where displacement, force and velocity do not affect each other. In other words, any change in one of the properties will adversely affect at least one of the remaining ones. The measurements are performed in out-of-plane mode on 2 cm diameter samples in low frequency range (0.01-1 Hz) under application of low voltage (2 V). Measurement curves of three main actuator properties are plotted together against the frequency resulting in operation point as the intersection point of those curves. Additionally the deviations in actuator performance are assessed to reflect the actuators' reproducibility and their production process stability by means of standard deviation. Knowledge about the relation between actuator properties and the value of operation point will facilitate evaluation of the existing CNT actuator against its potential applications.

Research paper thumbnail of Quantum limit of the Carnot engine

Fortschritte der Physik, 2006

To what extent can the design principles of a macroscopic machine be down-scaled to the nanoscopi... more To what extent can the design principles of a macroscopic machine be down-scaled to the nanoscopic level? This question pertains to machine functions as diverse as information processing or energy conversion. Here we will be concerned with the class of Carnot engines. Our minimal model consists of a single spin coupled to an oscillator sandwiched between two thermal baths at