SBIR Phase I: Novel Emergency Communication System for Mines

This Small Business Innovation Research (SBIR) Phase I project takes a new approach to detecting time-dependent fields for communication in cases where RF signals are strongly attenuated, such as in mines, caves, tunnels, and dense building environments. It is known that lower-frequency electromagnetic (EM) waves or magnetic near fields (MNF) are able to penetrate absorbing media to greater distances than higher frequency fields. A variety of communication means are used in mines. Some rely on wireless networks , others depend on electrical continuity of conductors (incumbent electrical wiring or leaky-feeders) ? which can be compromised in a disaster, and others depend on very large high-power loop antennas operating at low frequency. However, loop receive antennas (based on Faraday?s law of induction) produce smaller voltages in lower-frequency fields unless the product of the number of turns, N, and area, A, of the loop is correspondingly increased. Recent evidence suggests that engineered magneto-electric (ME) devices (laminates of magnetostrictive and electroactive materials) can be more sensitive than loop antennas at lower frequencies. This project aims to optimize ME devices as well as their associated electronic and software systems as receivers for low-frequency communications in mine emergencies. The broader impact/commercialization potential of this project extends immediately to communication during inspection of underground water mains, conduits, and tunnels. Each of these areas of commercial application place different demands on system size and weight, communication range and channel capacity. In a broader sense, the technical developments targeted in this program should advance the potential of ME devices for other applications presently under development, including short-range wireless power transfer (such as for in-vivo therapy, medication management, or health monitoring), personal communication bubbles, and magnetometry. Engineered ME devices offer advantages of simple, robust structure, and relative ease of fabrication at small dimensions compared to coils. Engineered ME devices exhibit magneto-electric coupling coefficients that are many orders of magnitude greater than those of naturally occurring ME materials.