Blar i USN Open Archive på forfatter "Halvorsen, Einar"
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Architecture-independent power bound for vibration energy harvesters
Halvorsen, Einar; Le, Cuong Phu; Mitcheson, P.D.; Yeatman, Eric M. (Journal article; Peer reviewed, 2013)The maximum output power of energy harvesters driven by harmonic vibrations is well known for a range of specific harvester architectures. An architecture-independent bound based on the mechanical input-power also exists ... -
Comparative performance of voltage multipliers for MEMS vibration-based energy harvesters
Truong, Binh Duc; Le, Phu Cuong; Halvorsen, Einar (Journal article; Peer reviewed, 2018)This paper investigates by numerical simulation the performance of an electrostatic vibration energy harvester when it is electrically configured in two different diode-capacitor multiplier topologies. The complete ... -
Competing anticlastic and piezoelectric deformation at large deflections
Salmani, Hamed; Hanke, Ulrik; Halvorsen, Einar (Peer reviewed; Journal article, 2021)In bending of a purely elastic beam or plate, it is well established that the cross-sectional shape changes character with decreasing bending radius-of-curvature and that the transition can be characterized by the Searle ... -
Constitutive Equations of Piezoelectric Layered Beams with Interdigitated Electrodes
Nguyen, Cuong Hung; Hanke, Ulrik; Halvorsen, Einar (Peer reviewed; Journal article, 2018)This paper establishes the constitutive equations, or linear two-port models, of piezoelectric layered beams with interdigital electrodes (IDEs). The effect of the nontrivial field on the transduction is analyzed. Based ... -
DRIE Si Nanowire Arrays Supported Nano-Carbon Film for Deriving High Specific Energy Supercapacitors On-Chip
Lu, Pai; Chen, Xuyuan; Øhlckers, Per; Halvorsen, Einar; Hoffmann, Martin; Müller, Lutz (Peer reviewed; Journal article, 2021)Supercapacitor is a promising solution to storage of pulsed energy generated by MEMS energy harvesting systems, relying on its faster charging/discharging capability than secondary battery. To improve the energy density ... -
Electric control of power extracting end-stop for MEMS vibration energy harvesting
Truong, Binh Duc; Le, Cuong Phu; Halvorsen, Einar (Journal article; Peer reviewed, 2014)This experimental work investigates a technique to further improve performance of vibration energy harvesters under displacement-constrained operation. Previously, a device concept based on end-stops acting as additional ... -
Electrode optimization of an electret-based vibration generator in slot-effect configuration
Le, Phu Cuong; Halvorsen, Einar (Journal article; Peer reviewed, 2018)This paper offers insights into optimization of electret-based energy harvesters made of two patterned electrodes facing movable electret strips parallelized with a pitch p. The effective electrode dimension of such harvester ... -
Electrostatic energy harvesters and fundamental limits to power
Halvorsen, Einar (Journal article; Peer reviewed, 2018)Analysis of fundamental performance limits to vibration energy harvesting reveal how damping and electromechanical coupling affect performance both for narrow and wide-band excitations. This talk summarizes the performance ... -
Equivalent-circuit model for slot-effect configuration of an electret-based generator
Le, Cuong Phu; Renaud, Michael; Halvorsen, Einar (Journal article; Peer reviewed, 2016)This paper presents a completely analytical method to build a lumped-model for an electret-based energy harvester. The harvester consists of two patterned electrodes facing movable electret patterns in a slot-effect ... -
Experimental validation of damping model for a MEMS bistable electrostatic energy harvester
Nguyen, Cuong Hung; Nguyen, Duy Son; Halvorsen, Einar (Journal article; Peer reviewed, 2014)This paper validates lumped models of an asymmetric bistable MEMS electrostatic energy harvester against measurements. A conventional model of constant damping coefficient turns out to be ineffective in predicting or ... -
Experimentally verified model of electrostatic energy harvester with internal impacts
Truong, Binh Duc; Le, Cuong Phu; Halvorsen, Einar (Journal article, 2015)This paper presents experimentally verified progress on modeling of MEMS electrostatic energy harvesters with internal impacts on transducing end-stops. The two-mechanical-degrees-of-freedom device dynamics are described ... -
Experiments on power optimization for displacement-constrained operation of a vibration energy harvester
Truong, Binh Duc; Le, Cuong Phu; Halvorsen, Einar (Journal article; Peer reviewed, 2015)This paper presents experiments on how to approach the physical limits on power from vibration energy harvesting under displacement-constrained operation. A MEMS electrostatic vibration energy harvester with voltage-control ... -
Fundamental issues in nonlinear wideband-vibration energy harvesting
Halvorsen, Einar (Journal article, 2013)Mechanically nonlinear energy harvesters driven by broadband vibrations modeled as white noise are investigated. We derive an upper bound on output power versus load resistance and show that, subject to mild restrictions ... -
Graphene synthesized on porous silicon for active electrode material of supercapacitors
Su, Binbin; Chen, Xuyuan; Halvorsen, Einar (Journal article; Peer reviewed, 2016)We present graphene synthesized by chemical vapour deposition under atmospheric pressure on both porous nanostructures and flat wafers as electrode scaffolds for supercapacitors. A 3nm thin gold layer was deposited on ... -
Integration of Carbon Nanotubes in Microsystems: Local Growth and Electrical Properties of Contacts
Haugen, Tormod Bjørnetun; Ta, Bao Quoc; Halvorsen, Einar; Hoivik, Nils; Aasmundtveit, Knut (Journal article; Peer reviewed, 2013)Carbon nanotubes (CNTs) have been directly grown onto a silicon microsystem by a local synthesis method. This method has potential for wafer-level complimentary metal-oxide-semiconductor (CMOS) transistor-compatible ... -
Local Synthesis of Carbon Nanotubes in Silicon Microsystems: The Effect of Temperature Distribution on Growth Structure
Ta, Bao Quoc; Haugen, Tormod Bjørnetun; Hoivik, Nils; Halvorsen, Einar; Aasmundtveit, Knut (Journal article; Peer reviewed, 2013)Local synthesis and direct integration of carbon nanotubes (CNTs) into microsystems is a promising method for producing CNT-based devices in a single step, low-cost, and wafer-level, CMOS/MEMS-compatible process. In this ... -
Low power electronic interface for electrostatic energy harvesters
Phan, Tra Nguyen; Azadmehr, Mehdi; Le, Cuong Phu; Halvorsen, Einar (Journal article; Peer reviewed, 2015)This paper presents design and simulation of a power electronic interface circuit for MEMS electrostatic energy harvesters. The designed circuit is applicable to highly miniaturized electrostatic harvesters with small ... -
MEMS electrostatic influence machines
Le, Cuong Phu; Halvorsen, Einar (Journal article; Peer reviewed, 2016)This paper analyses the possibility of MEMS electrostatic influence machines using electromechanical switches like the historical predecessors did two centuries ago. We find that a generator design relying entirely on ... -
Modeling framework for piezoelectrically actuated MEMS tunable lenses
Abdelmeguid, Mahmoud Ahmed Farghaly; Akram, Muhammad Nadeem; Halvorsen, Einar (Peer reviewed; Journal article, 2016)We report a modeling framework for evaluating the performance of piezoelectrically actuated MEMS tunable lenses. It models the static opto-electromechanical coupling for symmetric configurations of piezoelectric actuators ... -
On the lateral instability analysis of MEMS comb-drive electrostatic transducers
Truong, Binh Duc; Le, Phu Cuong; Halvorsen, Einar (Peer reviewed; Journal article, 2019)This paper investigates the lateral pull-in effect of an in-plane overlap-varying transducer. The instability is induced by the translational and rotational displacements. Based on the principle of virtual work, the ...