Abstract
The thermodynamic cycle of a resonant, MEMS-based, micro heat engine is characterized. The micro heat engine is an external combustion engine made of a cavity encapsulated between two membranes. The cavity is filled with saturated liquid–vapor mixture working fluid. Heat is added to and rejected from the engine at a frequency corresponding to the resonant frequency of the engine. Both pressure–volume and temperature-entropy diagrams are used to investigate the thermodynamic cycle of the resonant micro heat engine. The results show that the working cycle is nearly rectangular in shape and consists of two constant temperature processes and two constant volume processes. We hypothesize that major sources of irreversibility in the engine are heat transfer over finite temperature differences during heat addition and rejection, heat transfer into and out of engine thermal mass, viscous losses due to liquid working fluid motion, and heat escape from the engine to the surroundings. The maximum pressure and volume changes measured inside the engine cavity are 45 Pa and 0.55 mm3, respectively. The results show that for a heat addition of 1 mJ, the engine operates over a very small temperature difference. The small operating temperature difference is mostly attributable to the large thermal storage of the engine structure, the membranes and the wicks. The measured second law efficiency of the micro heat engine is 16 %.
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Bardaweel HK, Anderson MJ, Richards RF, Richards CD (2008) Optimization of the dynamic and thermal performance of a resonant micro heat engine. J Micromech Microeng 18:104014. doi:10.1088/0960-1317/18/10/104014
Bardaweel H, Anderson M, Richards R, Richards C (2010) Cyclic operation of a MEMS-based resonant micro heat engine: experiment and model. J Appl Phys 107:104901. doi:10.1063/1.3372755
Cengel Y, Boles M (1994) Thermodynamics an engineering approach. McGraw Hill, New York
Cho J, Richards C, Jiao J, Bahr R, Richards R (2006) Design and characterization of a MEMS thermal switch. In: Proceedings of the solid-state sensors, actuators, and microsystems workshop
Cho JH, Weiss LW, Richards CD, Bahr DF, Richards RF (2007a) Power production by a dynamic micro heat engine with an integrated thermal switch. J Micromech Microeng 17:S217–S223. doi:10.1088/0960-1317/17/9/S02
Cho J, Wiser T, Richards C, Bahr D, Richards R (2007b) Fabrication and characterization of thermal switch. Sens Actuators A 133:55–63. doi:10.1016/j.sna.2006.03.033
Cho JH, Richards CD, Richards RF (2008) A facility for characterizing the steady-state and dynamic thermal performance of microelectromechanical system thermal switches. Rev Sci Instrum 79:034901. doi:10.1063/1.2894147
Epstein AH et al (1997) Micro-heat engines, gas turbines and rocket engines: the MIT micro engine project. In: Proceedings of the 28th AIAA fluid dynamics conference
Frechette L, Lee C, Arslan S, Liu Y-C (2003) Design of a microfabricated Rankine cycle steam turbine for power generation. In: Proceedings of the ASME IMECE 2003: IMECE2003-42082
Fu K, Knobloch AJ, Marinez FC, Walther DC, Fernandez-Pello C, Pisano AP, Liepmann D (2001) Design and fabrication of a silicon based MEMS rotary engine. In: Proceedings of the ASME IMECE 2001: MEMS-23925
Herrault F, Crittenden T, Yorish S, Birdsell E, Glezer A, Allen MG (2008) A self-resonant, MEMS-fabricated, air-breathing engine. In: Proceedings of the solid-state sensors, actuators, and microsystems workshop, Hilton Head Island, South Carolina
Isomura K, Murayama M, Teramoto S, Hikichi K, Endo Y, Togo S, Tanaka S (2006) Experimental verification of the feasibility of a 100 W class micro-scale gas turbine at impeller diameter of 10 mm. J Micromech Microeng 16:S254–S261. doi:10.1088/0960-1317/16/9/S13
Jacobson SA, Epstein AH (2003) An informal survey of Power MEMS. In: Proceedings of the ISMME2003-K18, Tsuchiura, Japan
Mehra A, Zhang X, Ayon AA, Waitz IA, Schmidt MA, Spadaccini CM (2000) A six-wafer combustion system for a silicon micro gas turbine engine. J Microelectromech Syst 9:517–527
Nakajima N, Ogawa K, Fujimasa I (1989) Study on micro engines—miniaturizing stirling engines for actuators and heat pumps. In: Proceedings of the IEEE Micro electro mechanical system workshop
Vlassak J, Nix W (1992) A new bulge test technique for the determination of young’s modulus and Poisson’s ratio of thin films. J Mater Res 7:3242–3249. doi:10.1557/JMR.1992.3242
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Bardaweel, H., Richards, R., Richards, C. et al. Characterization of the thermodynamic cycle of a MEMS-based external combustion resonant engine. Microsyst Technol 18, 693–701 (2012). https://doi.org/10.1007/s00542-012-1496-y
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DOI: https://doi.org/10.1007/s00542-012-1496-y