Variable Emittance Electrochromic Materials
for Spacecraft Thermal Control

Our Unique, Patented Technology in a Nutshell

Construction

• Thin (< 0.5 mm), flexible, entirely solid state panel construction. Hermetically sealed.
• Can be affixed to any surface. Conform to any shape/size.
• Variable area: 1 cm^2 to 1 m^2 (custom tailorable), any shape or size, as easy as cutting with scissors.
• Impervious to bending, flexing, micrometeroids, bulletholes etc. during operation. Extreme physical durability.
• Very light weight: about 0.12 g/cm^2 (1.2 kg/m^2).

 See construction, principle of operation, device photos

Space Durability

• Solar Wind, gamma radiation to 7.6 MRad,
• "Thermal Vacuum", cycling in space vacuum over -40 ^ degrees C to + 60 ^ degrees C over several months.
• Temperature durability from -95 to + 85 ^ degrees C.
• Space UV exposure tested to 520 h.
• Indefinite shelf life.
• These and other tests carried out at Jet Propulsion Laboratory (JPL), NASA-Goddard Space Flight Center.
  
   See construction, principle of operation, device photos

Thermal, Spectral and Electrochromic Properties
The Largest Known, Demonstrated Emittance Variation in the world, coupled with low Solar Absorptance:

• 0.53 variation in Emittance (,).
• Tailorable Emittance ranges from 0.15 to 0.85.
• Solar Absorptance ("(s)) < 0.25. Also independently
  adjustable (0.2 to 0.6).
• Quasi-independent control of IR and Visible region electrochromism.

 See spectra and other electrochromic data.

 IR-Region
 Visible-Region

Switching and Durability
Very fast switching and long lasting

• Switching times < 10 s. With more sophisticated programming
  of Controller, < 2 s.
• Cyclabilities > 10^4 cycles for all devices. Tailorable to 10^5
  cycles in select devices.

Power
Very Low Power

• +/- 1.5 VDC, 40 microwatts/cm^2.

Controller
Sophisticated Controller

• Separate, microprocessor-based modular Controller originally designed for spacecraft use (NASA's ST5 science mission).
• Control individual devices in arrays of up to 100 or more electrochromic devices ("pixels") of varied sizes.
• PC-interfaced, PDA-interfaced, or independent.
• Programmed in C++: Modifiable and tailorable.
• Fully space-proofed and tested, with rad-hard parts.
  Individual control of devices in arrays of more than 100 devices.
• Optimize switching times, lifetime.
• Inexpensive.

 See photos of Controller

Patented
Rock solid patent protection

• US patents: #5,995, 273 (1999); #6,033, 592 (2000).
• Several other US patents pending.
• Canadian, European and other nation patents.

Principle of Operation

• Modulation by Conducting Polymer of IR, Visible or other light reflected from Au, Pt or other metal. (The Conducting Polymer (CP) is the active electrochromic).
  
   See principle of operation

Arrays

• Up to 100-device arrays demonstrated. No theoretical limit to number of devices in an array.
• Dimension of devices in arrays: All possible individual device dimensions, from 0.5 cm^2 to 1 m^2.\
• Sophisticated PC or PDA-interfaceable Controller (see above). Very low power consumption.
• Ideal for signaling and information applications from military vehicles or soldier uniforms.

 See array performance photos.

Custom tailoring, application to all types of spacecraft

• Custom-tailored devices and arrays to suit your thermal control, size, and other needs.
• Suitable for any substrate type, from metal (e.g. Al) to composite to thermoplastic.
• Suitable for spacecraft types ranging from microspacecraft to Space Based Radars to interplanetary spacecraft to Mars balloons.

Very Low Cost

• Less than 1/10 the cost of mechanical louvers and other extant spacecraft thermal control technologies.

Our Publications in this Field

 Click here for a list of references and links.
 
 

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