This Small Business Innovation Research (SBIR) Phase I project investigates the feasibility of using through-air ultrasound data communications for wireless sensors. Traditional RF-based wireless communications for small-form-factor devices like sensors or mobiles use carrier frequencies of hundreds of MHz to several GHz. The associated electronic receivers and transmitters must be designed to handle these high speeds. This results in substantial power dissipation so that regular battery replacements are required, which are both difficult and costly. Ultrasonic communications use low frequency carriers, from a few tens of kilohertz to a few MHz, which enables an order-of-magnitude reduction in the power consumption of the communication electronics. In preceding academic research, a custom-designed ultrasonic receiver integrated circuit (IC) was field tested. The IC achieves a ten-fold reduction in power consumption over the state-of-the-art RF-based receivers. To prepare this technology for the commercial arena more technical work will be conducted in understanding the effect of reverberations on system performance in real sensor environments, in increasing the communication-distance range from the present value of 10m, and in designing ultrasonic transducers customized for data communications. The anticipated end-result is a low-cost, ultralow- power ultrasonic-communication module that consumes significantly lower power than any commercially available wireless communication system. The broader impact/commercial potential of this project derives from the fact that low cost and ultra-low power wireless sensors enabled by using ultrasound have a vast array of applications in industrial, structural and environmental monitoring. Several of the potential applications have a significant societal impact; examples include border surveillance, air-pollution monitoring, forest-fire detection, greenhouse monitoring, machine-health monitoring, and wastewater monitoring. Further, the use of interference-free ultrasound will expand the applications of wireless sensor networks in RF regulated environments like hospitals. This will be a leap forward in the safety and environmental sustainability of wireless sensor networks
