A while back Brent’s paper was accepted at ICRA:
B. Griffin and C. Detweiler. Resonant Wireless Power Transfer to Ground Sensors from a UAV. IEEE International Conference on Robotics and Automation (ICRA), 2012, Accepted.
We will be there presenting this work next month in St. Paul Minnesota. There is also a video that goes along with the paper:
We are currently making a lot of progress in the NIMBUS Lab developing sensors and control systems to autonomously align the flier to optimize the power transfer. Hopefully we will be posting results on that work over the summer.