Radiation constrained charging utility optimization for human safety

Most existing studies for wireless power transfer technology focus on the energy charging efficiency issues, but overlook its threat to human safety due to its high electromagnetic radiation (EMR). Though no study results have generally provided clear evidence of a relationship betweenEMRand the health impairments, there have been some statistically significant findings in certain positive cases. Exposure to high EMR has been widely identified as a threat to human health. Its potential risks include but are not limited to tissue impairment, brain tumor, and mental diseases. In this chapter, we take the risks of such radiation into consideration, and present the Safe Charging Problem (SCP), aiming at achieving the best trade-off between the charging efficiency and EMR safety. We pay special attention to the following problem: given a set of wireless power chargers and rechargeable devices, how to schedule the chargers so that the devices can obtain more power, while no location exceeds the EMRsafety threshold.We prove the hardness of SCP, and propose a near optimal solution. We also present extensive simulation results and testbed results to verify our theoretical findings.