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MEMS: Micro Systems for Asset Visibility and Monitoring

Micro-electro-mechanical systems may be a key technology
to achieving anticipatory logistics support.

The Army must explore and leverage technological innovations to maximize warfighting effectiveness as it transforms from the Current Force to the Future Force and achieves joint and expeditionary capabilities. The Focused Logistics Joint Functional Concept, approved by the Joint Requirements Oversight Council, serves as a framework for achieving these capabilities. A key component of Focused Logistics is the ability to provide rapid response, asset visibility, and improved agility tailored to the sustainment of forces at the strategic, operational, and tactical levels.

Transforming to this new environment will require the fusion of operations, intelligence, and logistics enterprise domains to support rapid and dynamic operations. New technology solutions, integrated systems, and support processes will be needed if logisticians are to effectively transform materiel management, distribution, transportation, and warehousing operations to meet future demands. Future capabilities will require anticipatory logistics support, which can be provided by embedded diagnostic sensors that anticipate failures and initiate resupply or replacement activities to sustain mission readiness.

One promising new technology, micro-electro-mechanical systems (MEMS), has the potential to allow logisticians to begin proactively planning and providing focused logistics support to Soldiers today. Through MEMS, it is possible to envision a day in the not-so-distant future when assets can talk—sensing problems and automatically providing alerts in advance of impending failure, or providing status information on demand on the situation and condition (or “health”) of assets. From a logistician’s perspective, it would be a considerable leap forward not only to see assets at rest or in motion but also to know the condition of those assets and to have corresponding life-cycle histories that show the factors contributing to the assets’ failure in operational settings. MEMS-based sensors, coupled with automatic tracking devices, can help logisticians in “getting smart with logistics.”

What are MEMS?

MEMS combine modern electronics technologies with mechanical systems on a very small scale to sense, control, and act on events of interest. In simple terms, MEMS technology is a way of combining computer smarts with sensors to analyze and react to changing situations. As illustrated at left, MEMS technology provides integrated systems capabilities on a truly “micro” scale. From monitoring the health of assets on and off transportation platforms to improving life-cycle management, securing cargo, or displaying recent enemy movements on a vehicle mapping system, MEMS technology promises to be pervasive in Army Transformation.

MEMS Pilot Test

The Army Logistics Transformation Agency (LTA) is conducting proof-of-concept testing to validate the application of MEMS near-real-time sensor data and controls to logistics business processes. Before initiating proof-of-concept testing, LTA conducted an analysis to identify and test MEMS product capabilities, analyze applicable business processes, and document potential design concepts.

The overall goals of MEMS technology exploration include—
• Capitalizing on advances in MEMS technology to achieve proactive logistics support, improve decisionmaking, and support Army Transformation.
• Providing timely and accurate information to Soldiers and logisticians on the viability of assets by using MEMS integrated sensor data collection, reporting, and asset health monitoring.
• Developing an integrated framework and standard approach for collecting, reporting, controlling, and monitoring asset health within the framework of a common logistics operating environment.
• Improving life-cycle management and asset visibility by combining “sense” capabilities with radio frequency identification (RFID) and other communication technologies.

Individual protective equipment (IPE) was selected as the first pilot test application. The IPE includes Joint Service Lightweight Integrated Suit Technology (JSLIST) suits, gloves, boots, and other gear designed to protect against chemical and biological hazards. Applying MEMS technology to IPE will help quantify the benefits of using integrated MEMS-based sensors within a representative Army logistics management situation.

IPE was chosen as the initial pilot test in order to build on previous work completed by LTA to standardize asset marking and improve asset visibility and control of this critical commodity. Also, since IPE is a shelf-life item and contains both rubberized materials and adhesives, the environment in which a given contract lot is kept can affect selection of valid test samples for surveillance, shelf-life testing and extension decisions, and overall product life-cycle management.

The MEMS pilot recommendation was approved by the Department of the Army Automatic Identification Technology Senior Steering Committee in March 2004. While IPE can be used in desert, arctic, and jungle environments, LTA decided to focus the MEMS IPE pilot test on capturing and determining environmental extremes and alert thresholds for a desert environment. Testing in a desert environment also would help maximize effectiveness of IPE management in current Army operations in Iraq. The MEMS IPE pilot test includes the monitoring of assets in storage at Blue Grass Army Depot, Kentucky, monitoring of assets in transit, monitoring of environmental conditions in a desert environment, and recovery operations at Pine Bluff Arsenal, Arkansas.

Using Radio Frequency Identification

Management of IPE to support rapid deployment of forces presents many challenges. Individual sizes of chemical gear must be stored, inventoried, sorted, tracked, and issued against established shelf-life criteria and relevant messages that affect the serviceability of a given manufacturing lot. For early-deploying units, two sets of serviceable, basic-load IPE ensembles are stored and managed at the installation level. For later deployers, IPE is managed at the depot level through the Army Chemical Defense Equipment Go-to-War Program. Gaining necessary visibility of IPE assets across the board and synchronizing current and future requirements against the quantity of stock on hand and relevant serviceability data are continuing readiness challenges.

To meet this challenge, MEMS technology has been combined with active RFID devices. Use of MEMS with RFID can help track IPE assets and monitor the shelf-life and environmental factors that affect the execution of surveillance, receipt, recovery, inspection, and life-cycle management processes. MEMS with RFID provide standoff asset visibility, self-reporting communications, and data storage functions capable of measuring, recording, alerting, and providing immediate feedback to Soldiers and logisticians on the viability of assets. While other communication methods or platforms could be used, RFID has the advantage of a sizeable, existing Department of Defense (DOD) infrastructure that allows for the rapid injection of MEMS sensor capabilities with minimal cost.

MEMS, RFID, and the Desert Environment

To quickly populate MEMS RFID tags for shipment to Iraq, standard two-dimensional barcodes located on IPE boxes were read with a Windows-based handheld computer. The same handheld device then was used to write requisite data onto the MEMS tags. This approach is similar to how DOD handles current RFID tags. However, it includes a means of setting up alert-triggering thresholds through the current fixed and mobile readers based on measurements that fall outside of an acceptable parameter. Unlike current tags, alerts also can be triggered if a shelf-life date is exceeded or is close to being exceeded, depending on the amount of warning desired. As part of the pilot test, over 100 pallets of IPE were tagged with MEMS devices and shipped to Iraq.

Actual MEMS data gathered from those shipments are represented in the chart above. These data provide a histogram of temperatures measured on an hourly basis from June through September 2005 and currently are being used to help determine the effects of a harsh temperature environment on IPE assets. IPE assets were shipped from the continental United States (CONUS) to Iraq, where they were kept in outside open storage and then in outside covered storage before being moved into a climate-controlled warehouse. At the end of September, the associated MEMS devices were returned to CONUS for further analysis. MEMS can provide a powerful tool for management of IPE assets in an adaptive environment.

Based on the results of the pilot testing, LTA is working with Army Soldier Systems Center at Natick, Massachusetts, to validate the required trigger threshold for temperature alerts for MEMS devices used specifically for IPE assets. A test plan was developed to mimic environmental conditions observed in Iraq within a controlled laboratory setting. Accelerated aging on IPE test articles, followed by live agent testing, will help determine the effect of a desert environment on the serviceability of IPE. Previously, JSLIST assets were tested to temperatures below what were recorded by MEMS devices in Iraq. As illustrated below, IPE temperature peaks were experienced while the items were in open, uncovered storage. Testing conducted as part of this pilot will provide valuable information on the negative effects of temperature on IPE shelf life, but additional testing will be required by IPE program managers to fully quantify effects within desert, arctic, and jungle climates.

MEMS and In-Transit Visibility

The MEMS IPE proof-of-concept evaluation includes an in-transit visibility (ITV) alert feature to assist logisticians in anticipating failures and initiating resupply or replacement activities before failures occur. Specifically, if a temperature parameter or shelf-life date is exceeded when the MEMS device is read using a handheld reader, an alert will be provided automatically through the DOD ITV server to the Soldier on the ground. The built-in alert feature will allow logisticians to manage assets more proactively by anticipating requirements and engaging necessary support actions when and where they are needed. In addition, MEMS will enable Soldiers to more effectively determine asset viability and suitability for onward shipment and use.

An interface to the Mobility Inventory Control Accountability System (MICAS), currently in development, will improve end-to-end life-cycle management and monitoring of IPE. MICAS is an automatic identification technology-enabled tool used by the Army and Air Force to provide improved IPE asset visibility and inventory control and to automate business processes associated with issue, receipt, storage, inventory, tracking, and shelf-life management. By integrating MEMS with the Army’s MICAS IPE shelf-life management tool, the location, quantities, status, and environmental history of IPE can be tracked to improve asset visibility, surveillance, receipt, recovery, inspection, and selection of valid cross samples for shelf-life testing. The MICAS MEMS integration is scheduled for completion in late 2005.

As depicted in the chart above, by applying MEMS technology to IPE, managers and Soldiers on the ground can see the location and condition of assets on hand, the length of time those assets have been at a particular location, and the corresponding environmental data (temperature and humidity) for that location over time. The preliminary results from the MEMS IPE pilot test have been positive.

Once MEMS RFID technology is fully validated, it can be expanded to other assets and integrated with future sense-and-respond logistics capabilities. The initial analysis for applying MEMS to medical supplies is underway; more information on this MEMS application will be available in the near future. Other logistics application areas include perishable subsistence, maintenance diagnostics and prognostics, ammunition, hazardous materials, containerized engine tracking, and component and subcomponent environment “health monitoring.”

Moving forward with exploration and experimentation with MEMS technology will provide logisticians a unique opportunity to transform logistics to achieve more timely and proactive Soldier support. As the technology becomes more widespread and is integrated with command and control applications, it will help combatant commanders in gaining near-real-time situational awareness and improving strategic responsiveness with more timely, condition-based information. ALOG

John Yates is a senior Army Staff logistician at the Army Logistics Transformation Agency at Fort Belvoir, Virginia. He has a B.S. degree in electrical and computer engineering from the University of South Carolina and completed the Navy Acquisition Logistics Career Intern Program.