Lasers provide a new way to analyse priceless art without damage
29 May 2014 03:07 PM
UK scientists, working
on an international project to conserve precious works of art, have found a new
way to analyse paintings without having to remove even a tiny speck of the
paint to inspect the layers below.
Using laser spectroscopy, a
method that uses light to probe under the surface of an object, the
international team has developed a new, non-invasive way to identify the
chemical content of the paint layers present.
This new technique will reduce
the risk of damage to precious paintings, often worth thousands or even
millions of pounds, when conservation and restoration work is being carried
out.
The new approach is derived from
a technique called Spatially Offset Raman Spectroscopy (SORS). It was
originally developed by UK researchers at the Science and Technology Research
Council’s (STFC) Central Laser Facility within the Research Complex at
Harwell. Now they have joined forces with researchers from the Institute for
the Conservation and Promotion of Cultural Heritage (ICVBC), part of
Italy’s National Research Council (CNR) to adapt this technology to test
paintings without having to destroy any part of them.
The SORS technique involves
shining the laser light onto an opaque object. A small number of photons (light
‘particles’) will scatter back, changing colour according to the
different paint components they represent, and allowing the scientists to
analyse the chemical composition in depth.
Professor Pavel Matousek, from
STFC’s Central Laser Facility, explained. “Building on our earlier
SORS research, we’ve transformed the method to allow us to probe the
painted layers for the first time,” he said. “We’ve called it
Micro-SORS because we can analyse the layers at the micrometer scale, rather
than the usual millimetre scale”.
For comparison of scale, a human
hair is about 100 micrometers wide.
Dr Claudia Conti, a scientist at
the ICVBC in Italy, said, “When I heard about the potential of SORS and
how it could be applied, I realised the huge contribution this method of
analysis could bring to the conservation of artworks.”
The research team tested the
Micro-SORS method by collecting data from the light scattered across a surface
of painted layers, artificially prepared to mimic a real painting. They
isolated the light signals of the individual paint layers, enabling them to
assess the chemical make-up of each layer.
The next step in the
team’s research is to optimise the sensitivity and depth of penetration,
and apply the technique to real artwork.
One of the leading experts in
the UK on the preservation of cultural heritage is Professor May Cassar,
Director of UCL’s Centre for Sustainable Heritage and the Programme
Director for the UK Science and Heritage Research Programme. She has a keen
interest in innovative methods that allow for the study of artefacts in a
non-invasive way and, although not directly involved in this project, she said
of this research that, “In the field of cultural heritage, the objects
being studied are unique artworks. Removing even a minute sample for analysis
is only justified when essential data cannot be obtained in any other way. The
application of this novel Micro-SORS technique has potential for non-invasive
study of artworks and is definitely worth further
exploration.”
Dr Conti said, “Micro-SORS
promises to make a major contribution to the knowledge and conservation of
artworks. We will continue to work with our colleagues at the CLF to take
forward this important research. Our ultimate goal is to develop the Micro-SORS
technology into a portable device that can be used in the field.
“
The original SORS technique has
already been applied to a number of problems, including non-invasive breast
cancer diagnosis and bone disease diagnosis.The Science and Technology
Facilities Council (STFC) has also launched a spin-out company, Cobalt Light
Systems, which uses the SORS technology and has recently developed products for
scanning liquids in unopened bottles for airport security, and in
pharmaceutical quality control.
Notes to
editors
- Images of a painting being
analysed using Micro-SORS can be obtained from the STFC press office.
Email Marion O’Sullivan or tel: 01235
445627.
- An article describing this
work will appear in the June 2014 issue of Applied Spectroscopy. It is
available online now.
- Professor Pavel Matousek is
based at the Central Laser Facility, within the Research
Complex at Harwell, at STFC’s Rutherford Appleton Laboratory in
Oxfordshire, UK.
- Dr Conti and her colleagues are
based at L’Istituto per la
Conservazione e la Valorizzazione dei Beni Culturali (ICVBC) in Milan,
Italy.
Contact
For more information you can
contact:
Marion O’Sullivan - STFC Press Office
Rutherford Appleton Laboratory
Tel: 01235 445627
Mobile: 07824 888990