Environmental monitoring by thin film nanocomposite sensors for cultural heritage preservation

Environmental control is a crucial issue in cultural heritage preservation as it especially relates to sensitive artwork and antique object conservation. Storage and transport of artworks and antiques are operations requiring precise control of the environment. Current technology trends lead to miniaturization of environmental sensor devices in which low power dissipation and advanced non-contact or remote monitoring methods appear to offer significant advantages. In the above context, nanocomposite materials represent innovative alternative solutions for high sensitivity temperature and relative humidity (RH) sensing. The control of both of these parameters, together with the exposure to ultraviolet radiation, is important in minimizing aging and deterioration of art and antique objects. New schemes reported here consider the classes of CNx and CoCl2 nanocomposites. First, CNx thin films are synthesized on Si substrates by reactive pulsed laser ablation of graphite targets in N-2 atmosphere to form capacitive sensors. On the other hand, CoCl2 polymer matrix composite films are produced by spin coating or casting of the composite polymer/CoCl2 on planar glass substrates. These latter systems present a new class of optically interrogated photonic sensors featuring powerless sensing head and remote monitoring capabilities. The prototype devices proposed for use in art conservation and museum applications have been tested under controlled environmental conditions and their performance is seen to be comparable, and in some cases superior, to conventional monitoring solutions. (C) 2010 Elsevier B.V. All rights reserved.