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Conformal phased surfaces for wireless powering of bioelectronic microdevices


Wireless powering could enable the long-term operation of advanced bioelectronic devices within the human body. Although both enhanced powering depth and device miniaturization can be achieved by shaping the field pattern within the body, existing electromagnetic structures do not provide the spatial phase control required to synthesize such patterns. Here, we describe the design and operation of conformal electromagnetic structures, termed phased surfaces, that interface with non-planar body surfaces and optimally modulate the phase response to enhance the performance of wireless powering. We demonstrate that the phased surfaces can wirelessly transfer energy across anatomically heterogeneous tissues in large animal models, powering miniaturized semiconductor devices (<12 mm3) deep within the body (>4 cm). As an illustration of in vivo operation, we wirelessly regulated cardiac rhythm by powering miniaturized stimulators at multiple endocardial sites in a porcine animal model.

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Figure 1: Phased surface wireless powering system.
Figure 2: Wireless powering performance of the phased surface.
Figure 3: Performance variation with geometry and thermal characteristics.
Figure 4: Wireless powering of microdevices in pig abdomen and neck.
Figure 5: In vivo wireless cardiac pacing in pig.

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We acknowledge support from grants from the Singapore Institute for Neurotechnology, US National Science Foundation (ECCS-1351687), the US National Institutes of Health (National Institute of Biomedical Imaging and Bioengineering grant R21EB020894) and the Hong Kong Innovation and Technology Fund (ITS/087/14).

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Authors and Affiliations



H.F.T., A.S.Y.P. and J.S.H. jointly supervised this work. D.R.A., Y.T., D.W., A.M., S.H., C.S., Z.D., F.Y., A.S.Y.P. and J.S.H. built and characterized the wireless powering system. Y.T., A.M., S.H., S.-Y.L., Z.Z., Z.-Y.Z., H.F.T., A.S.Y.P. and J.S.H. performed the in vivo experiments. D.R.A., H.F.T., A.S.Y.P. and J.S.H. wrote the manuscript.

Corresponding author

Correspondence to John S. Ho.

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Competing interests

This work relates to patent PCT/US2015/052642.

Supplementary information

Supplementary Information

Supplementary methods, figures and tables. (PDF 2723 kb)

Supplementary Video 1

Magnetic-field amplitude as the position of a bone structure is varied along the lateral direction (x direction, at z = 25 mm). (MOV 1238 kb)

Supplementary Video 2

Magnetic-field amplitude as the position of a bone structure is varied along the vertical direction (z direction, at x = 0 mm). (MOV 694 kb)

Supplementary code—sample data

Sample data for the MATLAB scripts. (TXT 76 kb)

Supplementary code

MATLAB scripts. (TXT 4 kb)

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Agrawal, D., Tanabe, Y., Weng, D. et al. Conformal phased surfaces for wireless powering of bioelectronic microdevices. Nat Biomed Eng 1, 0043 (2017).

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