Luca Alessandrini is an innovator and designer from Italy who is making waves in the world of acoustic engineering.  The last big disruption in musical materials is noted as the rise of carbon fibre in the 1970s. Modern acoustic materials have since become disposable, often made from plastics or their derivatives.

The materials used in speakers, amplifiers and musical instruments are often unsustainable. Plastics are toxic when burned and produce a lot of waste as they are rarely recyclable. Even wooden parts are often found to be off key with nature. To Luca, this sounded like the perfect opportunity for innovation.

In search of an alternative, the young engineer set about exploring biomaterials. These materials are designed and made to specifically interact with biological systems. Although they are usually used in medical applications, Luca instead began researching their acoustic properties.

Throughout his research, he carried out more than 50 different experiments. He tested the density and stiffness of materials from flax to animal fibres and measured how fast sound waves passed through each. His aim was to create a sustainable, biodegradable and better sounding material. The most musical material he found was silk.

Taking his findings one step further, Luca crafted the world’s first silk violin. “The violin is a proof of concept,” he said. “I wanted to create a musical instrument to show the unique properties of the material. I wanted to show how it works, and how it reacts to sound. The violin shows that it is possible to make more natural materials and have them perform better than others that exist.”

Crafting the instrument

Plywood is one of the most common materials used in acoustics. This, however, is something Luca is keen to change. Made of individually glued sheets, no manufacturing technique exists to control the inner structure. Additionally, the process produces a lot of waste and can prove costly.

Using Luca’s technique, a cloth made from silk fibres is impregnated with resin. By setting the weave of the cloth, the maker has full control over the exact structure of the material. Unlike plywood, this means the instruments acoustic properties are completely customisable. Luca’s innovation marks the first time any such innovation has been seen in modern music.

So unusual is the project, it has even piqued the interest of violin makers of Cremona in Italy, home of famed luthiers Amati and Stradivari.  To create his prototype, Luca turned instead to a German maker for help. For the expert in moulding instruments from carbon fibre, the silk violin followed much the same pattern. The end results, however, were markedly different.

First, sheets of woven silk are cut out in the shape of the violin. At the same time, the inside of a mould is painted with Luca’s special bio-resin and lined with fabric. With each layer of fabric, the silk is saturated with more resin. Once complete, the whole mould is vacuum packed, removing any air bubbles. Then, still under the vacuum, it goes into an oven to bake the layers together and harden the shell.

A second prototype played even more on the unique properties of silk, this time with a little help from some spiders. Teaming up with the Oxford Silk Group, Luca explored the acoustic qualities of silk from the golden orb weaver spider. Each spider produces threads that are five times the strength of steel and remarkably elastic.

Cutting threads to 35cm long and spinning them together, Luca placed three strands along the body of his second violin. The threads were inlaid into resin beneath the bridge of the instrument. With each stroke of the bow across the strings above, the spider silk below vibrates and adds extra resonance. Along with an improved resin recipe, the spider silk gave the new violin a rich and beautiful sound.

Future sounds

Protecting his innovation for the future, Luca has filed a patent for the technology in Italy. He hopes that once perfected, the new material could replace plastic, carbon and even wooden parts. By controlling the weave of the silk cloth, as well as the density and direction of fibres, Luca can tune and customise its acoustic properties. With this technique, Luca can produce a material that is light, cheap and sustainable. Above all, his super material remains acoustically superior to those currently available.

Putting it to the ultimate test, Luca developed a third prototype; this time a bass amplifier. He took apart an existing amplifier and replaced all the wooden acoustic parts with his resin. The end product came in at around a third of the weight of the original. His ultimate goal is to replace all heavy, inefficient materials with natural fibres at a very low cost.

Luca is currently focussed on his new start-up, Fibreacoustics Ltd. Over the next year, he wants to build partnerships and collaborate with others in the industry, license the technology and develop his own bespoke and highly customised violins.

Speaking of his future plans, Luca said: “We decided to treat this gap in the acoustic industry as a space for innovation. We propose a high-performance, sustainable and fully customisable solution.” The patented technology can be compatible with almost any musical instrument or acoustic device. This could include speakers, headphones, amplifiers and even mobile phone accessories.