Engineers at the Tokyo Tech have found a new approach to taking a measurement over an extended area. The technique is based on coupled chaotic oscillators, which are highly sensitive electronic circuits that can interact wirelessly through low-frequency, low-power electromagnetic coupling. [38] A cheap, biocompatible white powder that luminesces when heated could be used for non-invasively monitoring the temperature of specific organs within the body. [37] The Internet of Things (IoT) is a technology classification that includes home appliances and other items embedded with electronics, software, sensors, and actuators that connect and exchange data. One key IoT technology is optical fiber sensing. [36] In a pilot study, researchers from North Carolina State University and Haverford College have used naturally arising acoustic vibrations-or sound waves-to monitor the state of granular materials. [35]