@article{palagummi_yuan_2016, title={An efficient low frequency horizontal diamagnetic levitation mechanism based vibration energy harvester}, volume={9799}, ISSN={["1996-756X"]}, DOI={10.1117/12.2218914}, abstractNote={This article identifies and studies key parameters that characterize a horizontal diamagnetic levitation (HDL) mechanism based low frequency vibration energy harvester with the aim of enhancing performance metrics such as efficiency and volume figure of merit (FoMv). The HDL mechanism comprises of three permanent magnets and two diamagnetic plates. Two of the magnets, aka lifting magnets, are placed co-axially at a distance such that each attract a centrally located magnet, aka floating magnet, to balance its weight. This floating magnet is flanked closely by two diamagnetic plates which stabilize the levitation in the axial direction. The influence of the geometry of the floating magnet, the lifting magnet and the diamagnetic plate are parametrically studied to quantify their effects on the size, stability of the levitation mechanism and the resonant frequency of the floating magnet. For vibration energy harvesting using the HDL mechanism, a coil geometry and eddy current damping are critically discussed. Based on the analysis, an efficient experimental system is setup which showed a softening frequency response with an average system efficiency of 25.8% and a FoMv of 0.23% when excited at a root mean square acceleration of 0.0546 m/s2 and at frequency of 1.9 Hz.}, journal={ACTIVE AND PASSIVE SMART STRUCTURES AND INTEGRATED SYSTEMS 2016}, author={Palagummi, S. and Yuan, F. G.}, year={2016} }
 @article{palagummi_yuan_2017, title={An enhanced performance of a horizontal diamagnetic levitation mechanism-based vibration energy harvester for low frequency applications}, volume={28}, ISSN={["1530-8138"]}, DOI={10.1177/1045389x16651152}, abstractNote={ This article identifies and studies key parameters that characterize a horizontal diamagnetic levitation mechanism–based low frequency vibration energy harvester with the aim of enhancing performance metrics such as efficiency and volume figure of merit. The horizontal diamagnetic levitation mechanism comprises three permanent magnets and two diamagnetic plates. Two of the magnets, lifting magnets, are placed co-axially at a distance such that each attracts a centrally located magnet, floating magnet, to balance its weight. This floating magnet is flanked closely by two diamagnetic plates which stabilize the levitation in the axial direction. The influence of the geometry of the floating magnet, the lifting magnet, and the diamagnetic plate is parametrically studied to quantify their effects on the size, stability of the levitation mechanism, and the resonant frequency of the floating magnet. For vibration energy harvesting using the horizontal diamagnetic levitation mechanism, a coil geometry and eddy current damping are critically discussed. Based on the analysis, an efficient experimental system is setup which showed a softening frequency response with an average system efficiency of 25.8% and a volume figure of merit of 0.23% when excited at a root mean square acceleration of 0.0546 m/s2 and at a frequency of 1.9 Hz. }, number={5}, journal={JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES}, author={Palagummi, Sri Vikram and Yuan, Fuh-Gwo}, year={2017}, month={Mar}, pages={578–594} }
 @article{palagummi_zou_yuan_2015, title={A Horizontal Diamagnetic Levitation Based Low Frequency Vibration Energy Harvester}, volume={137}, ISSN={["1528-8927"]}, DOI={10.1115/1.4030665}, abstractNote={This paper investigates a horizontal diamagnetic levitation (HDL) system for vibration energy harvesting in contrast to the vertical diamagnetic levitation (VDL) system recently proposed by Wang et al. (2013, “A Magnetically Levitated Vibration Energy Harvester,” Smart Mater. Struct., 22(5), p. 055016). In this configuration, two large magnets, alias lifting magnets (LMs), are arranged co-axially at a distance such that in between them a magnet, alias floating magnet (FM), is passively levitated at a laterally offset equilibrium position. The levitation is stabilized in the horizontal direction by two diamagnetic plates (DPs) made of pyrolytic graphite placed on each side of the FM. This HDL configuration mitigates the limitation on the amplitude of the FM imposed in the VDL configuration and exploits the ability to tailor the geometry to meet specific applications due to its frequency tuning capability. A simple circular coil geometry is designed to replace a portion of the pyrolytic graphite plate without sacrificing the stability of the levitation for transduction. An experimental setup exhibits a weak softening frequency response and validates the theoretical findings; at an input root mean square (RMS) acceleration of 0.0434 m/s2 and at a resonant frequency of 1.2 Hz, the prototype generated a RMS power of 3.6 μW with an average system efficiency of 1.93%.}, number={6}, journal={JOURNAL OF VIBRATION AND ACOUSTICS-TRANSACTIONS OF THE ASME}, author={Palagummi, S. and Zou, J. and Yuan, F. G.}, year={2015}, month={Dec} }
 @article{palagummi_zou_yuan_2015, title={A diamagnetically stabilized horizontally levitated electromagnetic vibration energy harvester}, volume={9431}, ISSN={["1996-756X"]}, DOI={10.1117/12.2077630}, abstractNote={This article investigates a horizontal diamagnetic levitation (HDL) system for vibration energy harvesting. In this configuration, two large magnets, alias lifting magnets, are arranged co-axially at a distance such that in between them a magnet, alias floating magnet, is passively levitated at a laterally offset equilibrium position. The levitation is stabilized in the horizontal direction by two diamagnetic plates made of pyrolytic graphite placed on each side of the floating magnet. This HDL configuration permits large amplitude vibration of the floating magnet and exploits the ability to tailor the geometry to meet specific applications due to its frequency tuning capability. Theoretical modeling techniques are discussed followed by an experimental setup to validate it. At an input root mean square (RMS) acceleration of 0.0434 m/s2 (0.0044 grms) and at a resonant frequency of 1.2 Hz, the prototype generated a RMS power of 3.6 μW with an average system efficiency of 1.93%. Followed by the validation, parametric studies on the geometry of the components are undertaken to show that with the optimized parameters the efficiency can be further enhanced.}, journal={ACTIVE AND PASSIVE SMART STRUCTURES AND INTEGRATED SYSTEMS 2015}, author={Palagummi, S. and Zou, J. and Yuan, F. G.}, year={2015} }
 @article{palagummi_yuan_2015, title={An optimal design of a mono-stable vertical diamagnetic levitation based electromagnetic vibration energy harvester}, volume={342}, ISSN={["1095-8568"]}, DOI={10.1016/j.jsv.2014.12.034}, abstractNote={A detailed analysis of a mono-stable vertical diamagnetic levitation (VDL) system for optimal vibration energy harvesting is presented. Initial studies showed that simple analytical techniques such as the dipole model and the image method provide useful guideline for understanding the potential of a diamagnetic levitation system, however, it is discussed here that the more accurate semi-analytical techniques such as the thin coil model and the discrete volume method are needed for quantitative optimization and design of the VDL system. With the semi-analytical techniques, the influence of the cylindrical geometry of the floating magnet, the lifting magnet and the diamagnetic plate are parametrically studied to assess their effects on the levitation gap, size of the system and the natural frequency. For efficient vibration energy harvesting using the VDL system, ways to mitigate eddy current damping and a coil geometry for transduction are critically discussed. With the optimized parameters, an experimental system is realized which showed a hardening type nonlinearity. The results show an overall efficiency of 1.54 percent, a root mean square (rms) power output of 1.72 µW when excited at a peak acceleration of 0.081 m/s2 and at a frequency of 2.1 Hz.}, journal={JOURNAL OF SOUND AND VIBRATION}, author={Palagummi, S. and Yuan, F. G.}, year={2015}, month={Apr}, pages={330–345} }
 @article{wang_palagummi_liu_yuan_2013, title={A magnetically levitated vibration energy harvester}, volume={22}, ISSN={["0964-1726"]}, DOI={10.1088/0964-1726/22/5/055016}, abstractNote={In this paper a novel electromagnetic vibration type energy harvester that uses a diamagnetic levitation system is conceptualized, designed, fabricated, and tested. The harvester uses two diamagnetic plates made of pyrolytic graphite between which a cylindrical magnet levitates passively. Two thick cylindrical coils, placed in grooves which are engraved in the pyrolytic graphite plates, are used to convert the mechanical energy into electrical energy efficiently. The geometric configurations of the coils are selected based on the field distribution of the magnet to enhance the efficiency of the harvester. A thorough theoretical analysis is carried out to compare with experimental results. At an input power of 103.45 μW and at a frequency of 2.7 Hz, the harvester generated a power of 0.74 μW with a system efficiency of 0.72%. Both theoretical and experimental results show that this new energy harvesting system can capture low frequency broadband spectra.}, number={5}, journal={SMART MATERIALS AND STRUCTURES}, author={Wang, X. Y. and Palagummi, S. and Liu, L. and Yuan, F. G.}, year={2013}, month={May} }
 @article{palagummi_yuan_2013, title={A vibration energy harvester using diamagnetic levitation}, volume={8688}, ISSN={["1996-756X"]}, DOI={10.1117/12.2009657}, abstractNote={In this paper a novel electromagnetic vibration type energy harvester which uses a diamagnetic levitation system is conceptualized, designed, fabricated, and tested. The harvester uses two diamagnetic plates made of pyrolytic graphite between which a cylindrical magnet levitates passively. Two archimedean spiral coils are placed in grooves which are engraved in the pyrolytic graphite plates, used to convert the mechanical energy into electrical energy efficiently. The geometric configurations of coils are selected based on the field distribution of the magnet to enhance the efficiency of the harvester. A thorough theoretical analysis is done to compare with the experiment results. At an input power of 103.45 μW and at a frequency of 2.7 Hz, the harvester generated a power of 0.744 μW at an efficiency of 0.72 %. Both theoretical and experimental results show that this new energy harvesting system is efficient and can capture low frequency broadband spectra.}, journal={ACTIVE AND PASSIVE SMART STRUCTURES AND INTEGRATED SYSTEMS 2013}, author={Palagummi, S. and Yuan, F. G.}, year={2013} }