Self-folding microcube antennas for wireless power transfer in dispersive media

One of the critical challenges in engineering is the wireless transfer of energy to power miniaturized electronic devices that have sizes smaller than the wavelength of electromagnetic radiation. Here, we describe a strategy to self-fold three-dimensional ( 3D) low gigahertz responsive antennas with small form factors using capillary forces. The antennas are sub-millimeter ( 500 x 500 x 500 mu m(3)) cubic devices with small form factors and hollow free space in their interior which could be used to embed other devices. We characterize and demonstrate the efficacy of these antennas in dispersive media. Remarkeably, we observe significantly higher power transfer with over an order of magnitude higher transfer efficiency as compared to similarly shaped planar antennas. Moreover, we show that the antennas can transfer on the order of 30 mW to power an LED, highlighting proof of concept for practical applications. Our findings suggest that self-folding polyhedral microantennas could provide a viable solution for powering tiny microdevices.Th is work was supported by the Portuguese Foundation for Science and Technology (Programa Operacional Temático Fatores de Competitividade COMPETE) Grants: SFRH/BD/63737/2009 FCT; PTDC/ EEA-TEL/65286/2006 FCT; PTDC/EEI-TEL/2881/2012; Fundo Comunitário Europeu FEDER and the National Science Foundation. We also acknowledge fi nancial support from the Army Research Offi ce (W911NF-09-2-0065). Th e authors thank Dr. Peter Armitage’s laboratory from Th e Johns Hopkins University for allowing the use of their network analyzer.info:eu-repo/semantics/publishedVersio