Wireless technology has been a boon to automatic identification processes—for example, in the form of radio-frequency-identification (RFID) tags to manage large stores of inventory. But RF/microwave energy may not always be the safest option for such tasks. For keeping track of ammunition and other hazardous materials that might turn explosive if exposed to the wrong form of energy, Visible Assets has developed wireless RuBee technology based on magnetism.
The company, founded in 2004, is growing a business based on licensing RuBee technology for base stations and tags in hazardous environments, such as weapons and ordnance warehouses, nuclear energy facilities, and explosives depots. RuBee, which is also known as the IEEE 1902.1 wireless standard, is extremely low power, with only the base stations emitting energy. It even works underwater and through steel, making it the only wireless standard for keeping track of stores in the most hazardous environments (see figure).
RuBee is probably best thought of as an alternative to RFID—working where RFID does not. Visible Assets, which boasts a fabless foundry for the purpose of designing RuBee chips, is not in the business of manufacturing RuBee products. Rather, the company has developed an Administrator-in-Training (AIT) licensing business to spread the technology where needed, licensing RuBee to well-established corporations working in a variety of different markets. Visible Assets already claims 34 patents related to RuBee trademarks, with more than 80 patents pending.
RuBee technology has been installed in numerous sites within the US Department of Energy Nuclear Labs—including Los Alamos, CA and Oak Ridge, TN—for inventory and asset tracking where RF energy would be considered unsafe. RuBee technology is also in use within the US Special Operations Command (SOCOM), the Crane Division of the US Naval Surface Warfare Center in Crane, IN (NAVSEA), and for XM2010 shot-counting tags at the US Army’s Fort Benning and Picatinny Arsenal.
Earlier this year, the US Navy certified the use of RuBee for Hazards of Electromagnetic Radiation to Ordnance (HERO) ordnance—for materials deemed both safe and unsafe. The US Navy’s own test report indicated that RuBee identification tags and handheld readers and base stations could be used at a zero safe separation distance (SSD) on these materials. The HERO SSD for other wireless technologies, such as RFID and Bluetooth, is typically 3 to 12 ft.
According to Jason August, Chief Technology Officer for Visible Assets, “HERO certification by the US Navy is one of the most demanding and important RF safety programs in the world. Because RuBee is magnetic, not RF, the Navy had to develop a new magnetic safety test protocol for fused ordnance under MIL STD 464C.” He adds: “These test protocols have all been based on worst-possible-case scenarios with large safety factors. The outcome that RuBee tags, readers and base stations can be safely used on HERO SAFE ordnance enables our existing military customers to expand their use of RuBee to all sensitive item stores.”
As noted earlier, RuBee uses magnetic energy—at a frequency of approximately 0.131 MHz. A tag does not emit energy but, rather, responds to a low-energy signal from a reader or base station, which sends out about 40 nW power. The tag is active, since it must store identifying information, and typically contains a small amount of memory, sensors, and a real-time clock. These RuBee tags, which are typically powered by a lithium coin-cell battery, have a battery life of around 25 years and a read range of 1 to 25 ft. They are immune to liquids and noise, and can even work through snow and soil.
One US Department of Energy (DoE) proof-of-concept study on RuBee showed that its tags can transmit status—including temperature, humidity, vibration—from inside a sealed containment vessel, eliminating costly and dangerous quarterly visual inspections. In addition to being perfectly safe for humans, RuBee devices are also immune from eavesdropping and other information security concerns.
Visible Assets, Inc.
195 Bunker Hill Ave.
Stratham, NH 03885