Scientists, musicians and instrument-makers have long sought to replicate great acoustics of instruments. A postgraduate student at Imperial College has developed a new composite material for violins – made with Golden Orb Spider silk
The quest for the great violin sound inevitably leads back to the violins produced in Cremona, Italy, by Antonio Stradivari (1644 – 1737). Scientific studies of these extraordinary musical objects over the last decade have suggested the acoustical superiority of the Stradivarius was due to the violins’ material properties. Biochemist Professor Joseph Nagyvary of Texas A&M University argued that it was due to the violin makers preparing the wood with salts of copper, iron and chromium. Berend Stoel of Leiden University in the Netherlands, using a CT scanner, proposed that it was due to the homogenous density of the Stradivarius’ wood. The recent violin project of Imperial College postgraduate Luca Alessandrini also lead him back to Cremona, but via the rarified material of spiders’ silk, specifically golden silk, spun by an Australian Golden Orb Spider.
Alessandrini was working for his Master of Science (MSc), in Innovation Design Engineering, a double Masters run between Imperial College and the Royal College of Art, exploring innovating with materials in design. ‘What I found out is that when you are in London you have the the chance to smell in advance what are the new fashions in the world design,’ he says, reflecting on the city’s intellectual, fashion and business culture that seeks out current boundaries in order to exceed them. ‘Last year’s fashion was augmented reality for example, this year’s is materials,’ so he thought, ‘let’s work with materials, let's work with scientists as well. It was very interesting to join workshops in University College London, in the Maker Institute.’
Alessandrini had always been involved in design, largely with furniture, through a short but inspirational course at the prestigious Accademia Italiana in Florence, and professionally at Italian furniture company Stilema. ‘I wanted to do a violin from the beginning,’ says Alessandrini. ‘I knew that it was something that was provocative, it's the most iconic musical instruments, it's the most difficult to make play properly. There is a culture behind the making of it. I wanted to work with biomaterials. I wanted to make this material that was better performing than wood ,so I started looking at what else was being used instead of wood.’
MOST POPULAR INSTRUMENT MATERIAL
Alessandrini discovered that over the last 20 years carbon fibre is the second most used material for making musical instruments, and looked to find a better-performing and more natural replacement. ‘I started looking at fibres, plant-derived fibres such as bamboo and flax, and also animal derived fibres such as silk and spiders silk.’ By calculating how effective different materials were at propagating vibration, he realised that the elasticity of silk made it more effective than carbon fibre.
‘It's resistant and very strong as well,’ says Alessandrini. ‘In a violin the strings are very, very tense, there is high pressure inside the instrument, [so] you need to have a very elastic material but also [one that is] very resistant and silk was just perfect. I had some PhD students from the Dyson School of Engineering who helped me and I felt confident enough to make a first prototype made out of silk and bioresin.’
He contacted a violin prototype maker from Stuttgart, rented some moulds and the first prototype was ready in three weeks; a timescale that would prove a revelation itself. The prototype maker said it would normally take 20 or 30 attempts with carbon fibre to get a similar quality of sound.
Alessandrini also made the pilgrimage to Cremona and was put in touch with 20 luthiers (someone who builds or repairs string instruments) via the Associazione Nazionale Liutai Artistici Italiani, an influential violin-making association. They were highly positive.
THE GOLDEN ORB WEAVER
While doing his calculations on the propagation properties of silk, Alessandrini had also explored spider’s silk. ‘It's super strong,’ he says. ‘The one I used is five times stronger than steel and is also incredibly elastic. This is something you don't usually find in the same material. After my research I concluded that due to the very high elasticity and the strength, the relatively low density, spider’s silk has the highest propagation velocity of the fibres, at least among the animal derived fibres.’
He contacted companies working with spider’s silk and eventually emailed Professor Fritz Vollrath, from the Department of Zoology at Oxford University, explaining his project. ‘I basically asked him to spin it out from this huge massive Australian spider, a huge Golden Orb Weaver, the spider you don't want to meet in your bedroom basically! In four days they managed to spin out three 35cm long strands. I asked them to be 35cm long, as that was the length of the violin.’
A MORE BALANCED SOUND
The luthiers suggested the most effective position for the strands would be in the body under the bridge (the part lifting the strings up), ‘We placed them under the feet of the bridge, and in the middle as well, directly where the vibration of the strings are transmitted. It was a tiny amount, but even this tiny amount was making a difference in two ways. It was already balancing the push of the strings inside the body of the violin because we have those strands under the bridge. And the strings are pushing the bridge down, and already in this tiny amount, this system was working differently, using the same setup as the first prototype.’
Taking the new prototype back to Cremona for evaluation the judgement form the luthiers was that the sound was better, it was more balanced. Since then Alessandrini showed the violin to Peter Sheppard Skaerved, a Grammy-nominated violinist and Viotti Lecturer at the Royal Academy of Music in London. Sheppard Skaerved said, ‘my encounter with the prototype instrument developed by Luca has filled me with excitement. This approach offers a tremendous opportunity to move forward instrument making, using new materials in a way I have long hoped.’ Alessandrini says that Sheppard Skaerved believed that the range of harmonics of this material was extremely high, ‘out of the range of regular violin. That was really really interesting.’
Alessandrini’s education has encouraged an experimental approach, which offers the possibility of crating something genuinely new and disruptive to conventional models. ‘After this I'm going down the start-up route, the new religion! I would like to work with research and development. I have a lot of ideas in my mind, a lot of projects I’d like to push forward. I'm listed in three incubators at the moment, next week I'm going to pitch for another one.’
