Violins made of wood treated with fungus need not hide their lights when compared to a Stradivarius, as a blind test has already demonstrated. However, these tonal masterpieces are only available as individually-made instruments. In order that these biotech violins may be manufactured in larger numbers, Empa researchers are currently working on optimizing and standardizing the fungal treatment.
What talented young violinist has not dreamt of playing on a Stradivarius, that non plus ultra of the violin-maker's art? Unfortunately, of course, these instruments are rare, and well beyond the budget of most musicians. "Imitations" of similar tonal quality are therefore very sought-after, and the Empa researcher Francis Schwarze has managed to achieve this feat with the help of a Swiss violin maker. By treating the wood with Physisporinus vitreus, a white-rot fungus which attacks and destroys certain structures in spruce, he was able to create a material with extraordinarily good tonal qualities. So good in fact that the new "fungus violin" put its own role model in the shade. At a specialist conference in 2009 two of the new instruments were compared in a blind test to a Stradivarius and both the jury of experts and the conference audience judged their sound to better than that of the violin made by the Italian Master of Cremona.
Schwarze now intends to develop a standardized biotechnological process so that sufficient fungally-treated wood can be produced to make instruments in respectable numbers. This is the only way that would allow an industrial partner interested in the technology to manufacture the violins on a quasi-"mass-produced" basis. In order to create the necessary bridge between science and industry it is vital to develop technologies which offer potential partners significant commercial advantages. In this case this means standardizing the wood treatment parameters to such an extent that a specific tonal quality can be guaranteed. This is not an easy task to accomplish with a material such as wood which is subject to natural fluctuations in quality.
Generous support from the Walter Fischli Foundation
In the Walter Fischli Foundation the Empa scientist has found financial support which will enable the "fungal violin" project continue. Explaining why he decided to provide funding for Schwarze's work, Walter Fischli, who is co-founder of the biomedical company Actelion and an enthusiastic hobby violinist, says "In my opinion it would have been unforgivable to allow such an interesting project one that so ideally links science and the art of violin making to wither for lack of funding." Fischli hopes that the Empa specialists will finally uncover the secret of why violin makers such as Stradivarius and Guarnerius managed to make instruments of such fantastic quality around 1700. Their craftsmanship is, of course, one decisive and undisputed factor but it seems that the wood they used also played a vital role. "Using modern science to explain the technical details of the material properties is something I find enormously interesting," says Fischli.
Developing a standard wood treatment process in an interdisciplinary way
The project, which commenced at the beginning of September and will run for three years, is led by Iris Brémaud, a specialist in the field of tonal woods. The French scientist is responsible for ensuring that the treatment with the white rot fungi P. vitreus and Xylaria longipes optimally "ennobles" samples of spruce and maple woods. In addition she is already in contact with Michael Baumgartner, the renowned instrument maker from Basel. Under his guidance the "fungus violins" using the treated wood will be created.
Before Empa can take delivery of the first violin, however, numerous tests on both treated and untreated wood samples must be carried out. Experts are currently systematically measuring the density of the wood, the speed of sound in it and its acoustic attenuation. Specialists in the field of ultrasonics are developing methods to determine where the fungus was active and where not. Other scientists expert in optical measurement techniques are using their specialist methods to create images showing how sound is radiated by the different woods and also complete instruments. The final steps should involve collaborations with specialists of psychoacoustics to understand how musicians and listeners perceive these "mushroom violins."
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