SITIS Archives - Topic Details
Program:  SBIR
Topic Num:  A10-109 (Army)
Title:  Sustainable Materials to Reduce Heat Signatures of Base Camps
Research & Technical Areas:  Materials/Processes

Acquisition Program:  
  Objective:  To develop materials and processes for use in sustainable military base camps to reduce heat signatures emanating from base camp through the use of advanced insulating materials in conjunction with thin-film thermoelectric generators and embedded batteries.
  Description:  Base camps require reduction in heat signature to maintain low-observable (or stealth) capabilities. Personnel and equipment within the base camps generate characteristic heat signatures that can reveal the location, presence of personnel and electronic equipment, and may provide some indication of activities and OPTEMPO. However, future base camps must reduce their heat signature for both the warfighter and the sustainment force. Emerging materials will be used in military base camps construction in many different climates to reduce heat signatures through the use of high efficiency insulating materials and thermoelectric coolers, which synergistically reduce radiated heat. Solid state devices can be embedded in layered composite fabric that offer high stiffness/high strength to weight ratios and are durable in harsh environments, such as desert heat. Such devices can be used to reduce the infrared radiation emanating from personnel or critical electronic equipment, e.g., for Command, Control, Communications, Computers, Information, Surveillance, and Reconnaissance (C4ISR). Thermoelectric Peltier devices can transfer heat from one side of the device to the other side against the temperature gradient (from cold to hot), with consumption of electrical energy. The power to drive the Peltier devices would be derived from the integrated photovoltaics on the top layer, or thin film batteries embedded into the composite structural material. The use of insulating composite fabric layers would help to insure thermal efficiency of the system. These relatively light-weight materials could reduce logistics burden of transporting heavy air conditioning (A/C) systems and the weight burden of deploying heavy electricity generators.

  PHASE I: Conduct research on the materials and processes to integrate innovative solid state power supply and thermal signature management capability into materials for military base camps. For example, emerging thin film inexpensive polycrystalline silicon based photovoltaic devices and thin film batteries, or supercapacitors, along with thermoelectric devices and insulators could be embedded into composite layers of tent fabric to provide 2,500 watts of electric power for an enclosure of typically 200 cubic meters for solid state cooling devices and other equipment. Investigate the use of lightweight (~1.5 g/cc) layered composite fabric with high stiffness (e.g., 80 GPa) and strength (~ 3.5 GPa), for use in in multiple environments, which contain insulating layers to provide additional thermal management. The target heat dissipation goal is ~10,000 BTU/h. Predict the efficiency of the composite multifunctional materials for thermal signature reduction. Demonstrate the capabilities at the laboratory scale, and down-select the most promising technologies for further development. Although the light weight feature is desirable, it can be sacrificed if necessary to achieve the other multifunctionalities.
  PHASE II: Design and test high strength lightweight multi-layered materials that for base camps shelters that protect personnel and equipment from inclement weather, high heat and humidity, and wind blown debris, which harness advanced embedded power systems to provide heat signature reduction on the surface of the base camp in military critical facilities, such as Command Control Communication, Computer, Intelligence, Surveillance and Reconnaissance (C4ISR) equipment and facilities. Develop manufacturing methods to produce these layered materials, with the approach of scaling up to full sized smart sustainable base camp construction materials

  PHASE III: Commercialize multi-layered construction materials that incorporate power generating and thermal management components for use in both military and non-military buildings and structures, including industrial environments. It is anticipated that commercialization will be achieved through co-operative agreements between the SBIR Company and their partners as well as well-established maanufacturers of innovative fabric structures, thermo-electric coolers, and photovoltaic design and manufacturing companies. The resulting structural components would not only provide structural protection, but would also provide low observable capabilities. In addition, the materials would be readily portable and could be used for tents used by campers in multiple and diverse climates.

  References:   1. O. Kunz, Z. Ouyang, J.Wong, and A. G. Aberle1, “Advances in Evaporated Solid-Phase-Crystallized Poly-Si Thin-Film Solar Cells on Glass (EVA),”Advances in OptoElectronics, Article ID 532351, pp. 1-7, 2008. 2. Ji Yeong Lee, Kay Hyeok An Jeong Ku Heo, and Young Hee Lee, “Fabrication of Supercapacitor Electrodes Using Fluorinated Single-Walled Carbon Nanotubes,” J. Phys. Chem. B, 107 (34), pp 8812–8815, 2003. 3. Hu, Eric; Kaynak, Akif; Li, Yuncang, “Development of a cooling fabric from conducting fibers: proof of concept,” Synthetic Metals, Vol 150, 2, pp.139-143, 2005. 4. Dubi, Y., and M. Di Ventra, "Thermoelectric Effects in Nanoscale Junctions," Nanoletters 9 (1), pp. 97-101, 2009.

Keywords:  base camps, heat signature, photovoltaics, insulating layers, Peltier device

Questions and Answers:
Q: The above topic description states "To develop materials and processes ..... through the use of advanced insulating materials in conjunction with thin-film thermoelectric generators and embedded batteries."

Our firm has developed a novel Infrared Electrochromics / Variable Emittance Technology for dynamic IR camouflage (broadband, both MWIR and LWIR) which has actually recently been successfully (preliminarily) tested in a classified program. In this, very thin (< 0.2 mm), flexible skins or panels are applied to any surface, including military base camp structures, infrastructure, tents, vehicles etc., for dynamic (i.e., adjustable) IR signature that can be made to match any background, and can lower the apparent temperature of a surface by more than 15 degrees C. The application of the panels/skins is generally by a unique, space-qualified, pressure-sensitive adhesive, but can be by other methods as well.

This technology may actually work far better than thermoelectric generators with embedded batteries, for reducing heat signatures of base camps. Also, power consumption is of the order of micro-watts per square centimeter, and voltage requirements are less than 3 VDC.

Q: Our question thus is: Are you limiting this topic strictly to thermoelectric generators and batteries, or are you open to consider other technologies which may potentially accomplish your objectives in a much better fashion?
We would be very grateful for a response.
A: I am willing to consider other technologies, such as advanced materials, which address the topic.
Q: Along similar lines as the previous comment, cooling the outside surface appears to run into problems with ultimate heat rejection. It seems that the important part remains to regulate the thermal emission on the outside surface of the enclosure.

Are you solely interested in materials that are designed to work in conjunction with specific TE cooler systems? Or is it sufficient to propose a material or device which can control thermal emission from any surface (which can also work without a cooling mechanism)?
A: A material or device which can control thermal emission from materials used in tent structures, without raising the interior temperature is acceptable.

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