| CPC A61B 8/4281 (2013.01) [A61B 8/4236 (2013.01); B32B 1/08 (2013.01); B32B 3/08 (2013.01); B32B 5/18 (2013.01); B32B 27/065 (2013.01); B32B 27/308 (2013.01); B32B 27/32 (2013.01); B32B 27/40 (2013.01); B32B 2266/025 (2013.01); B32B 2266/122 (2016.11)] | 24 Claims | 

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               1. An ultrasonic coupling device, comprising 
            a foam having an aperture; 
                a hydrogel comprising a water content of at least 10 wt % and a particle with at least one dimension less than 100 nm, wherein at least part of the hydrogel is located in the aperture of the foam; and 
                a near field communication device. 
               |