Inductive Telemetry of Multiple Sensor Modules

Abstract

One of the many challenges associated with sensor networks is how to transmit data and power the sensors. Sensing multiple parameters in the environment requires miniaturized sensor nodes, relatively powerful programming platforms to interface with and process the data, and reliable long-term power solutions. Batteries provide the most obvious power source as long as the modules are reasonably big (a few square centimeters), easily accessible, and few in number so that the batteries can be easily replaced or recharged. In the vision of ubiquitous computing, where modules are embedded into everyday objects, computer hardware should be invisible and replacing batteries isn't compatible with this vision. Several solutions to the power problem exist, such as reducing power consumption to the point where batteries can last the module's lifetime. Another solution is energy scavenging - that is, extracting energy from ambient sources such as vibrations, hear, light, and water. A new approach provides a power source and fast communication for miniaturized modules' sensor nodes using a 13.56 MHz carrier. Although its powering range is limited, this method is well suited for applications in which communication must be fast but the sensor modules are hard to access.