Journal Articles

Ruzziconi, L and Hajjaj, AZ (2026) Signature of combination resonance in chaotic dynamics and diverse quasi-periodic patterns of a hybrid-shaped MEMS, Nonlinear Dynamics, 114(14), 945, ISSN: 0924-090X. DOI: 10.1007/s11071-026-12631-4.

Andreou, P, Hajjaj, A, Mohammad-Pour, M, Theodossiades, S (2025) Jacobi-Ritz formulation for modal analysis of thick, anisotropic and non-uniform electric motor stator assemblies considering axisymmetric vibration modes, Meccanica, 61(1), 7, ISSN: 0025-6455. DOI: 10.1007/s11012-025-02071-6.

Bakhtiar, S, Hajjaj, A, Theodossiades, S (2025) Pendulum—driven flapping wind energy harvester for environmental monitoring, Smart Materials and Structures, 34(10), 105007, ISSN: 0964-1726. DOI: 10.1088/1361-665x/ae053e.

Draoui, H, Fang, Z, Dejene, F, Di Buono, A, Theodossiades, S, Hajjaj, A (2025) MEMS nitrogen sensor utilizing frequency localization for early detection of spent nuclear fuel canister failures, IEEE Sensors Journal, 26(2), pp.1785-1794, ISSN: 1530-437X. DOI: 10.1109/jsen.2025.3639146.

Fang, Z, Theodossiades, S, Jaber, N, Hajjaj, A (2024) Exploiting nonlinearity for sensitivity enhancement of novel tunable and low-power thin-film Piezoelectric-on-Silicon (TPoS) micromachined gas sensor, Measurement, 246, 116559, ISSN: 0263-2241. DOI: 10.1016/j.measurement.2024.116559.

Bakhtiar, S, Khan, FU, Fu, H, Hajjaj, AZ, Theodossiades, S (2024) Fluid Flow-Based Vibration Energy Harvesters: A Critical Review of State-of-the-Art Technologies, Applied Sciences, 14(23), pp.11452-11452, DOI: 10.3390/app142311452.

Ruzziconi, L, Jaber, N, Hajjaj, AZ, Younis, MI (2024) Subcombination internal resonance of the additive type in the response dynamics of micromachined resonators crossing the impacting threshold, Chaos, Solitons & Fractals, 189, pp.115615-115615, ISSN: 0960-0779. DOI: 10.1016/j.chaos.2024.115615.

Moon, H, Cho, H, Theodossiades, S, Hajjaj, A, Kim, T (2024) Development of nonlinear flat shell element with nonlinear thickness variation for highly flexible wind turbine blade, Renewable Energy, 235(November 2024), 121279, ISSN: 0960-1481. DOI: 10.1016/j.renene.2024.121279.

Ruzziconi, L and Hajjej Ep Zemni, A (2023) Multiple Internal Resonance Couplings and Quasi-Periodicity Patterns in Hybrid-Shaped Micromachined Resonators, Chaos, Solitons and Fractals, 177, ISSN: 0960-0779. DOI: 10.1016/j.chaos.2023.114145.

Andreou, P, Hajjaj, A, Mohammad-Pour, M, Theodossiades, S (2023) Analytical multiphysics methodology to predict vibroacoustics in PMSMs combining tangential electromagnetic excitation and tooth modulation effects, IEEE Transactions on Transportation Electrification, 10(3), pp.5997-6009, ISSN: 2332-7782. DOI: 10.1109/TTE.2023.3325350.

Fang, Z, Theodossiades, S, Hajjaj, A (2023) Triple sensing scheme based on nonlinear coupled micromachined resonators, Nonlinear Dynamics, 111(24), pp.22185-22213, ISSN: 0924-090X. DOI: 10.1007/s11071-023-08674-6.

Fang, Z, Theodossiades, S, Ruzziconi, L, Hajjaj, A (2023) A multi-sensing scheme based on nonlinear coupled micromachined resonators, Nonlinear Dynamics, 111(9), pp.8021-8038, ISSN: 0924-090X. DOI: 10.1007/s11071-023-08294-0.

farokhi, H, Rocha, RT, Hajjej Ep Zemni, A, Younis, MI (Accepted for publication) Nonlinear Damping in Micromachined Bridge Resonators, Nonlinear Dynamics, ISSN: 0924-090X. DOI: 10.1007/s11071-022-07964-9.

Hajjaj, A, Ruzziconi, L, Alfosail, F, Theodossiades, S (2022) Combined internal resonances at crossover of slacked micromachined resonators, Nonlinear Dynamics, 110(3), pp.2033-2048, ISSN: 0924-090X. DOI: 10.1007/s11071-022-07764-1.

Hajjaj, A, Corrigan, K, Mohammadpour, M, Theodossiades, S (2022) On the stability analysis of gear pairs with tooth profile modification, Mechanism and Machine Theory, 174, 104888, ISSN: 0094-114X. DOI: 10.1016/j.mechmachtheory.2022.104888.

Hajjaj, A and Jaber, N (2021) Controlling resonator nonlinearities and modes through geometry optimization, Micromachines, 12(11), 1381, DOI: 10.3390/mi12111381.

Hajjaj, A, Ortiz, J, Abdelkefi, A (2021) Nonlinear size-dependent modeling and dynamics of nanocrystalline arc resonators, International Journal of Mechanics and Materials in Design, 18(1), pp.105-123, ISSN: 1569-1713. DOI: 10.1007/s10999-021-09574-6.

Hajjej, AZ, Jaber, N, Alcheikh, N, Younis, MI (2019) A Resonant Gas Sensor Based on Multimode Excitation of a Buckled Microbeam, IEEE Sensors Journal, 20(4), pp.1778-1785, ISSN: 1530-437X. DOI: 10.1109/jsen.2019.2950495.

Hajjej, A, Jaber, N, Ilyas, S, Alfosail, FK, Younis, MI (2019) Linear and nonlinear dynamics of micro and nano-resonators: Review of recent advances, International Journal of Non-Linear Mechanics, 119, pp.103328-103328, ISSN: 0020-7462. DOI: 10.1016/j.ijnonlinmec.2019.103328.

Alcheikh, N, Hajjej, AZ, Younis, MI (2019) Highly sensitive and wide-range resonant pressure sensor based on the veering phenomenon, Sensors and Actuators A: Physical, 300, pp.111652-111652, ISSN: 0924-4247. DOI: 10.1016/j.sna.2019.111652.

Hajjej, AZ, Alfosail, FK, Jaber, N, Ilyas, S, Younis, MI (2019) Theoretical and experimental investigations of the crossover phenomenon in micromachined arch resonator: part II—simultaneous 1:1 and 2:1 internal resonances, Nonlinear Dynamics, 99(1), pp.407-432, ISSN: 0924-090X. DOI: 10.1007/s11071-019-05242-9.

Hajjej, AZ, Alfosail, FK, Jaber, N, Ilyas, S, Younis, MI (2019) Theoretical and experimental investigations of the crossover phenomenon in micromachined arch resonator: part I—linear problem, Nonlinear Dynamics, 99(1), pp.393-405, ISSN: 0924-090X. DOI: 10.1007/s11071-019-05251-8.

Hajjej, AZ, Chappanda, KN, Batra, NM, Hafiz, MAA, Costa, PMFJ, Younis, MI (2019) Miniature pressure sensor based on suspended MWCNT, Sensors and Actuators A: Physical, 292, pp.11-16, ISSN: 0924-4247. DOI: 10.1016/j.sna.2019.03.036.

Alfosail, FK, Hajjaj, AZ, Younis, MI (2019) Theoretical and Experimental Investigation of Two-to-One Internal Resonance in MEMS Arch Resonators, Journal of Computational and Nonlinear Dynamics, 14(1), 011001, ISSN: 1555-1415. DOI: 10.1115/1.4041771.

Hajjaj, AZ, Alfosail, FK, Younis, MI (2018) Two-to-one internal resonance of MEMS arch resonators, International Journal of Non-Linear Mechanics, 107, pp.64-72, ISSN: 0020-7462. DOI: 10.1016/j.ijnonlinmec.2018.09.014.

Hajjaj, AZ, Jaber, N, Hafiz, MAA, Ilyas, S, Younis, MI (2018) Multiple internal resonances in MEMS arch resonators, Physics Letters A, 382(47), pp.3393-3398, ISSN: 0375-9601. DOI: 10.1016/j.physleta.2018.09.033.

Hajjaj, AZ, Alcheikh, N, Hafiz, MAA, Ilyas, S, Younis, MI (2017) A scalable pressure sensor based on an electrothermally and electrostatically operated resonator, Applied Physics Letters, 111(22), pp.223503-223503, ISSN: 0003-6951. DOI: 10.1063/1.5003563.

Kazmi, SNR, Hajjaj, AZ, Hafiz, MAA, Costa, PMFJ, Younis, MI (2017) Highly Tunable Electrostatic Nanomechanical Resonators, IEEE Transactions on Nanotechnology, 17(1), pp.113-121, ISSN: 1536-125X. DOI: 10.1109/tnano.2017.2777519.

Hajjaj, AZ, Alcheikh, N, Younis, MI (2017) The static and dynamic behavior of MEMS arch resonators near veering and the impact of initial shapes, International Journal of Non-Linear Mechanics, 95, pp.277-286, ISSN: 0020-7462. DOI: 10.1016/j.ijnonlinmec.2017.07.002.

Hajjaj, AZ, Ramini, A, Alcheikh, N, Younis, MI (2017) Electrothermally Tunable Arch Resonator, Journal of Microelectromechanical Systems, 26(4), pp.837-845, ISSN: 1057-7157. DOI: 10.1109/jmems.2017.2676006.

Hafiz, MAA, Kosuru, L, Hajjaj, AZ, Younis, MI (2017) Highly Tunable Narrow Bandpass MEMS Filter, IEEE Transactions on Electron Devices, 64(8), pp.3392-3398, ISSN: 0018-9383. DOI: 10.1109/ted.2017.2716949.

Tella, SA, Hajjaj, AZ, Younis, MI (2017) The Effects of Initial Rise and Axial Loads on MEMS Arches, Journal of Vibration and Acoustics, 139(4), 040905, ISSN: 1048-9002. DOI: 10.1115/1.4036400.

Alcheikh, N, Hajjaj, AZ, Jaber, N, Younis, MI (2017) Electrothermally actuated tunable clamped-guided resonant microbeams, Mechanical Systems and Signal Processing, 98, pp.1069-1076, ISSN: 0888-3270. DOI: 10.1016/j.ymssp.2017.05.049.

Hajjaj, A, Hafiz, MA, Younis, MI (2017) Mode coupling and nonlinear resonances of MEMS arch resonators for bandpass filters, Scientific Reports, 7(1), 41820, ISSN: 2045-2322. DOI: 10.1038/srep41820.

Ramini, AH, Hajjaj, AZ, Younis, MI (2016) Tunable Resonators for Nonlinear Modal Interactions, Scientific Reports, 6(1), 34717, DOI: 10.1038/srep34717.

Hajjej, AZ, Alcheikh, N, Ramini, A, Al Hafiz, MA, Younis, MI (2016) Highly Tunable Electrothermally and Electrostatically Actuated Resonators, IEEE Journal of Microelectromechanical Systems, 25(3), pp.440-449, ISSN: 1057-7157. DOI: 10.1109/jmems.2016.2542338.

Hajjaj, AZ, Ramini, A, Younis, MI (2015) Experimental and analytical study of highly tunable electrostatically actuated resonant beams, Journal of Micromechanics and Microengineering, 25(12), pp.125015-125015, ISSN: 0960-1317. DOI: 10.1088/0960-1317/25/12/125015.

Conferences

Masabi, S, Li, T, Valentine, S, Di Buono, A, Hajjaj, A, Theodossiades, S (2026) An optimised metasurface-based vertical axis wind energy harvester for power-autonomous monitoring in piping and ducting systems. In 2025 IEEE 24th International Conference on Micro and Miniature Power Systems, Self-Powered Sensors and Energy Autonomous Devices (PowerMEMS); 2025 IEEE 24th International Conference on Micro and Miniature Power Systems, Self-Powered Sensors and Energy Autonomous Devices (PowerMEMS), pp.25-28, ISBN: 9798331567163. DOI: 10.1109/powermems66515.2025.11358504.

Bakhtiar, S, Hajjaj, AZ, Theodossiades, S (2025) Exploring Multi-Configuration Wind Energy Harvesting Using a Cantilever Beam-Plate Double-Pendulum System. In 2025 Energy Conversion Congress & Expo Europe (ECCE Europe), 2025 Energy Conversion Congress & Expo Europe (ECCE Europe), pp.1-5, DOI: 10.1109/ecce-europe62795.2025.11238926.

Fang, Z, Madeira, BP, Wang, C, Wang, Y, Zhao, C, Theodossiades, S, Hajjaj, AZ (2025) Study on Thermally Tuned Asymmetrical Coupled Resonator and its Gas Sensing Application. In 2025 23rd International Conference on Solid-State Sensors, Actuators and Microsystems (Transducers), pp.1692-1695, DOI: 10.1109/transducers61432.2025.11109207.

Draoui, H, Fang, Z, Theodossiades, S, Di Buono, A, Hajjaj, AZ (2025) A MEMS-Based Nitrogen Sensor for Early Detection of Spent Nuclear Fuel Canister Failures. In , Proceedings of Nuclear Plant Instrumentation and Control and Human Machine Interface Technology Npic and Hmit 2025, pp.573-581, DOI: 10.13182/NPICHMIT25-46798.

Draoui, H, Fang, Z, Theodossiades, S, Di Buono, A, Hajjaj, A (2024) Enhancing sensitivity using frequency localization factor in gas sensor based antisymmetric weakly coupled resonators. In 2024 IEEE 23rd International Conference on Micro and Miniature Power Systems, Self-Powered Sensors and Energy Autonomous Devices, PowerMEMS 2024, Tonsberg, Norway, pp.231-234, ISBN: 9798350380200. DOI: 10.1109/PowerMEMS63147.2024.10814500.

Andreou, P, Theodossiades, S, Hajjaj, A, Hajjaj, AZ, Mohammad-Pour, M, Ricardo Souza, M (2024) Reduced order model for modal analysis of electric motors considering material and dimensional variations. In 3th International Styrian Noise, Vibration & Harshness Congress: The European Automotive Noise Conference; SAE Technical Papers, Graz, Austria. DOI: 10.4271/2024-01-2945.

Fang, Z, Theodossiades, S, Dejene, F, Hajjaj, A (2024) Dynamics of a piezoelectric MEMS gas sensor based on coupled micromachined resonators. In 2023 IEEE 22nd International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS); 2023 IEEE 22nd International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS), Abu Dhabi, United Arab Emirates,ISBN: 9798350344219. DOI: 10.1109/powermems59329.2023.10417633.

Fang, Z, Theodossiades, S, Jaber, N, Hajjaj, A (2023) Gas sensor based on nonlinear coupled AlN-piezoelectric micromachined resonators. In Proceedings of IEEE Sensors, Vienna, Austria,ISBN: 9798350303872. DOI: 10.1109/SENSORS56945.2023.10324875.

Andreou, P, Zemni, AHE, Mohammad-Pour, M, Theodossiades, S (2022) Analytical multiphysics model for NVH prediction of a high-speed Surface-Permanent Magnet Synchronous Machine. In 53rd Spanish Congress of Acoustics 2022; Proceedings of the Spanish Congress of Acoustics, Alicante, Spain.

Hajjaj, AZ and Jaber, N (2021) Geometry Optimization for Resonator Nonlinearities and Modes Controlling. In ASME 2021 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Volume 9: 17th International Conference on Multibody Systems, Nonlinear Dynamics, and Control (MSNDC). DOI: 10.1115/detc2021-68529.

Alcheikh, N, Hajjaj, AZ, Younis, MI (2019) Wide Range Highly Sensitive Pressure Sensor Based on Heated Micromachined Arch Beam. In ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Volume 4: 24th Design for Manufacturing and the Life Cycle Conference; 13th International Conference on Micro- and Nanosystems. DOI: 10.1115/detc2019-97995.

Hajjaj, AZ, Jaber, N, Alcheikh, N, Younis, MI (2019) A Sensitive Resonant Gas Sensor Based on Multimode Excitation of a Buckled Beam. In ASME 2019 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Volume 4: 24th Design for Manufacturing and the Life Cycle Conference; 13th International Conference on Micro- and Nanosystems. DOI: 10.1115/detc2019-98148.

Hajjaj, AZ, Jaber, N, Alcheikh, N, Younis, MI (2019) A Sensitive Resonant Gas Sensor Based on Multimode Excitation of a Buckled Beam. In 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII), 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII). DOI: 10.1109/transducers.2019.8808228.

Hajjaj, AZ, Alfosail, FK, Younis, MI (2018) Experimental and Theoretical Study of Two-to-One Internal Resonance of MEMS Resonators. In ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Volume 6: 14th International Conference on Multibody Systems, Nonlinear Dynamics, and Control. DOI: 10.1115/detc2018-85539.

Hajjaj, AZ, Hafiz, MAA, Alcheikh, N, Younis, MI (2017) Scalable Pressure Sensor Based on Electrothermally Operated Resonator. In ASME 2017 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Volume 4: 22nd Design for Manufacturing and the Life Cycle Conference; 11th International Conference on Micro- and Nanosystems. DOI: 10.1115/detc2017-67785.

Hajjaj, AZ, Alcheikh, N, Younis, MI (2017) Effect of Initial Curvature on the Static and Dynamic Behavior of MEMS Resonators. In ASME 2017 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Volume 6: 13th International Conference on Multibody Systems, Nonlinear Dynamics, and Control. DOI: 10.1115/detc2017-67791.

Kazmi, SNR, Hajjaj, AZ, Costa, PMFJ, Younis, MI (2017) Electrostatically Tunable Nanomechanical Shallow Arches. In ASME 2017 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Volume 4: 22nd Design for Manufacturing and the Life Cycle Conference; 11th International Conference on Micro- and Nanosystems. DOI: 10.1115/detc2017-67845.

Kazmi, SNR, Hajjaj, AZ, Costa, PMFJ, Younis, MI (2017) Highly tunable NEMS shallow arches. In 2017 IEEE 17th International Conference on Nanotechnology (IEEE-NANO), pp.838-843, DOI: 10.1109/nano.2017.8117332.

Hajjaj, AZ, Al Hafiz, MA, Younis, MI (2016) Tunable Bandpass Filter Based on Electrothermally and Electrostatically Actuated MEMS Arch Resonator. In ASME 2016 International Mechanical Engineering Congress and Exposition, Volume 10: Micro- and Nano-Systems Engineering and Packaging. DOI: 10.1115/imece2016-66700.

Hajjaj, AZ, Alcheikh, N, Ramini, A, Al Hafiz, MA, Younis, MI (2016) Electrothermally Tunable Bridge Resonator. In ASME 2016 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Volume 4: 21st Design for Manufacturing and the Life Cycle Conference; 10th International Conference on Micro- and Nanosystems. DOI: 10.1115/detc2016-59892.

Ramini, A, Hajjaj, A, Younis, MI (2016) Experimental Investigation of 2:1 and 3:1 Internal Resonances in Nonlinear MEMS Arch Resonators. In ASME 2016 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Volume 6: 12th International Conference on Multibody Systems, Nonlinear Dynamics, and Control. DOI: 10.1115/detc2016-59538.

Hajjaj, AZ, Ramini, A, Alcheikh, N, Younis, MI (2016) Highly Tunable Electrothermally Actuated Arch Resonator. In ASME 2016 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Volume 6: 12th International Conference on Multibody Systems, Nonlinear Dynamics, and Control. DOI: 10.1115/detc2016-59898.

Ramini, A, Hajjaj, A, Younis, MI (2016) Experimental investigation of 2:1 and 3:1 internal resonances in MEMS arch resonators. In , Proceedings of the ASME Design Engineering Technical Conference. DOI: 10.1115/DETC201659538.

Hajjaj, AZ, Ramini, A, Alcheikh, N, Al Hafiz, MA, Younis, MI (2016) Electrothermally tunable bridge resonator. In , Proceedings of the ASME Design Engineering Technical Conference. DOI: 10.1115/DETC2016-59892.pdf.

Hajjaj, AZ, Ramini, A, Alcheikh, N, Younis, MI (2016) Highly tunable electrothermally actuated arch resonator. In , Proceedings of the ASME Design Engineering Technical Conference. DOI: 10.1115/DETC201659898.

Hajjaj, AZ, Al Hafiz, MA, Younis, MI (2016) Tunable bandpass filter based on electrothermally and electrostatically actuated mems arch resonator. In , ASME International Mechanical Engineering Congress and Exposition Proceedings Imece. DOI: 10.1115/IMECE201666700.

Chapters

Bakhtiar, S, Hajjaj, AZ, Fu, H, Theodossiades, S (2025) A Two-Body Low-Frequency Piezoelectric Wind Energy Harvester for Environmental Sensing. In Lecture Notes in Electrical Engineering, Springer Nature Singapore, pp.291-299, ISBN: 9789819747795. DOI: 10.1007/978-981-97-4780-1_22.