Experimental demonstration (VIDEO) Optica This video is under embargo. Please login to access this video. Caption The spherical ball lens retroreflector helps facilitate transmitter-receiver alignment, which maximizes power transfer efficiency. The system also automatically shifts to a safe low power delivery state if an object or a person blocks the line of sight between the transmitter and receiver. Credit Jinyong Ha, Sejong University Usage Restrictions None License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.