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Uncooled Carbon Microbolometer Imager


Liger, Matthieu (2006) Uncooled Carbon Microbolometer Imager. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/R7HB-GF96.


The discovery of infrared radiation two centuries ago and the theory of blackbody radiation one century later have given birth to the field of thermal imaging. Since then, researchers have devised numerous ways to detect infrared radiation. From World War II to the 1980s, semiconductor-based cooled photon detector arrays have reigned over the field of thermal imaging. Albeit limited to expensive, bulky systems used for military applications due to their cooling requirement they have been . The emergence of micromachining techniques in the 1980s however, have allowed for the development of uncooled, thermal detector arrays. Uncooled systems are expected to find more and more applications, especially in the civilian world.

Here we present a novel and simple way to fabricate uncooled infrared detectors suitable for integration into large-area arrays. The design is based on carbon obtained by means of polymer pyrolysis. We demonstrate how some electrical and thermal properties can be adjusted by process parameters, and then present the first micromachined carbon uncooled bolometer made of two-layers of self-supporting pyrolyzed-parylene carbon having different process-tuned properties.

Finally, based on this unique design and fabrication process, we develop a carbon bolometer array and demonstrate the thermal imaging capability by taking thermal images. Measurements show that the sensitivity to target temperature can be as low as 31mK and 44mK for 100us and 12us electrical signal integration time, respectively. This matches the current state of the art which is very promising considering the fact that this is the first time pyrolytic carbon has been used to fabricate a microbolometer array.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:bolometer; carbon; infrared; parylene; pyrolysis; uncooled thermal imaging
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Electrical Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Tai, Yu-Chong
Thesis Committee:
  • Tai, Yu-Chong (chair)
  • Yang, Changhuei
  • Psaltis, Demetri
  • Meng, Ellis
  • Painter, Oskar J.
Defense Date:13 September 2005
Non-Caltech Author Email:matthieu.liger (AT)
Record Number:CaltechETD:etd-09302005-174955
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:3841
Deposited By: Imported from ETD-db
Deposited On:12 Jan 2006
Last Modified:20 Apr 2020 21:29

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