Sensing/control/identification devices for machines are provided. The devices include a first stage having a rectification and power conditioning module configured to receive electromagnetic (EM) transmissions via waveguide confinement and convert said EM transmissions to electrical power, a communication interface module configured to receive power from the rectification and conditioning module and at least one of receive or transmit EM transmissions/communications via waveguide confinement, and a control module configured to receive EM transmission data from the communication interface for processing and/or preparing EM communications for transmission. The devices further include a second stage having a tunable control module configured to process and convert instructions or commands from the control module of the first stage into analog or digital signals and generate and transmit an output signal. At least one connection is between the first stage and the second stage to enable communication between the first and second stages.