Blar i USN Open Archive på forfatter "Halvorsen, Einar"
-
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 ... -
Optical performance of piezoelectrically actuated MEMS tunable lenses with various pupil geometries
Abdelmeguid, Mahmoud Ahmed Farghaly; Akram, Muhammad Nadeem; Halvorsen, Einar (Journal article; Peer reviewed, 2017)Abstract. A square geometry for the diaphragm of microelectromechanical systems (MEMS) tunable lenses with circular pupils is often used. This square diaphragm introduces aberrations that would not be present for a circular ... -
Power optimization and effective stiffness for a vibration energy harvester with displacement constraints
Truong, Binh Duc; Le, Cuong Phu; Halvorsen, Einar (Journal article; Peer reviewed, 2016)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 ... -
Power-electronic-interface topology for MEMS energy harvesting with multiple transducers
Truong, Binh Duc; Le, Phu Cuong; Halvorsen, Einar; Roundy, Shad (Journal article; Peer reviewed, 2018)Based on circuit simulations, this paper investigates a concept for a power electronic interface circuit for MEMS electrostatic energy harvesters. Two ordinary overlap-varying transducers are first electrically configured ... -
Self-tuning behavior of a clamped-clamped beam with sliding proof mass for broadband energy harvesting
Pillatsch, Pit; Miller, L.M.; Halvorsen, Einar; Wright, P.K.; Yeatman, Eric M.; Holmes, Andrew S. (Journal article; Peer reviewed, 2013)Real world systems rarely vibrate at a single resonance frequency and the frequencies drift over time. Tunable devices exist, but generally need additional energy to achieve frequency adaptation. This means that the benefits ... -
Statistics of a noise-driven elastic inverted pendulum
Halvorsen, Einar; Litak, Grzegorz (Journal article; Peer reviewed, 2015)Recently an elastic inverted pendulum structure was proposed as a means to make nonlinear energy harvesters. An effective dynamical model of this bi-stable system has an effective lumped mass that is dependent on the ... -
Trial functions for reduced-order models of piezoelectrically actuated microelectromechanical systems tunable lenses
Farghaly, Mahmoud A.; Hanke, Ulrik; Akram, Muhammad Nadeem; Halvorsen, Einar (Journal article; Peer reviewed, 2018)Piezoelectrically actuated microelectromechanical systems (MEMS) lens structures can be composed of a clamped square elastic diaphragm partially covered with a thin piezoelectric film leaving a circular transparent region ... -
A unified approach for the calculation of in-plane dielectric constant of films with interdigitated electrodes
Ræder, Trygve Magnus; Hanke, Ulrik; Halvorsen, Einar; Grande, Tor (Peer reviewed; Journal article, 2020)Interdigitated electrodes (IDEs) on dielectric films is an important electrode design in electrical components such as transducers and sensors. Further development and use of IDEs for characterization of the in-plane ... -
Which is better, electrostatic or piezoelectric energy harvesting systems?
Elliott, A.D.T.; Miller, L.M.; Halvorsen, Einar; Wright, P.K.; Mitcheson, P.D. (Journal article; Peer reviewed, 2015)This paper answers the often asked, and until now inadequately answered, question of which MEMS compatible transducer type achieves the best power density in an energy harvesting system. This question is usually poorly ...