SBIR Phase I: Novel Emergency Communication System for Mines

这个小型企业创新研究（SBIR）第一阶段项目采用了一种新方法来检测射频信号强烈衰减的情况下的通信时相关场，例如在矿山、洞穴、隧道和密集的建筑环境中。众所周知，低频电磁波（EM）或磁场（MNF）能够穿透吸收介质到比高频场更远的距离。矿井中使用多种通信手段。一些依靠无线网络，另一些依靠导体的电气连续性（现有的电线或漏电馈线）。这在灾难中可能会受到影响，而其他依赖于在低频下工作的非常大的大功率环路天线。然而，环路接收天线(基于法拉第？除非环路的匝数N和面积A的乘积相应增加，否则在低频场中产生较小的电压。最近的证据表明，工程磁电（ME）器件（磁致伸缩和电活性材料的层叠）在较低频率下比环形天线更敏感。该项目旨在优化ME设备及其相关的电子和软件系统，作为矿井紧急情况中低频通信的接收器。这项工程的广泛影响/商业化潜力，可立即扩展到检查地下水管、水管及隧道时的通讯。这些商业应用领域对系统尺寸和重量、通信范围和信道容量都有不同的要求。从更广泛的意义上说，这个项目的技术发展目标应该会推动ME设备在目前正在开发的其他应用中的潜力，包括短距离无线电力传输（如体内治疗、药物管理或健康监测）、个人通信气泡和磁强计。与线圈相比，工程ME器件具有简单，坚固的结构和相对容易的小尺寸制造的优点。工程ME器件表现出的磁电耦合系数比天然ME材料大许多个数量级。

This Small Business Innovation Research (SBIR) Phase I project takes a newapproach to detecting time-dependent fields for communication in cases where RFsignals 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 ofturns, 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 extendsimmediately 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 atsmall 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.