<i>&quot;The most recent paper to investigate the safety of ultrasound was just published [...] Of note is that this study used energy levels to tissue that were orders of magnitude higher than levels that uBeam’s system uses.&quot;</i><p>The abstract at <a href="http:&#x2F;&#x2F;www.sciencedirect.com&#x2F;science&#x2F;article&#x2F;pii&#x2F;S0041624X15001973" rel="nofollow">http:&#x2F;&#x2F;www.sciencedirect.com&#x2F;science&#x2F;article&#x2F;pii&#x2F;S0041624X15...</a>:<p><i>&quot;Demonstrated in vitro, 0.6 W of transcutaneous ultrasound power transfer to an implant.[...] with an average RF input to electrical charging efficiency of 20%&quot;</i><p>So, at best, 3W is <i>&quot;orders of magnitude higher than levels that uBeam’s system uses&quot;</i>. That will charge your remote, but not your phone.