With 3D printing the most common source of materials is synthetic plastics with dyes. For Melik C. Demirel these types of plastics have some performance issues. These plastics are derived from fossil fuels like crude oil and are then synthetically manufactured.
In a search for alternatives he has been studying a type of protein that exists in squid ring teeth (SRT). Material that can be drawn from this can be used to produce a thermoplastic. Thermoplastics are polymer materials that can melt, be formed and then solidify as the same material without degrading materials properties. This allows complex structures to be produced.
Rather than plunder the world’s oceans for squid, Demirel’s research group have are working on identifying the genetic sequence for various types of squid with a view to artificially manufacturing the material. The first squid to be sequenced is the European common squid.
For this, the researchers are using recombinant gene technology. Using the source from the European squid they have successfully inserted SRT protein genes into the bacterium Escherichia coli. This enables the microbe to produce plastic molecules through excretion. When the genetically modified bacteria in a suitable medium, the molecules that form the plastic can be readily extracted. The material can be produced in a hard or soft form.
3D printing is the process of creating a three-dimensional solid object of virtually any shape from a digital model. The process starts with a virtual design, created as a Computer Aided Design file using a modeling program. 3D printing is achieved using an additive process, where successive layers of material are laid down in different shapes.
The findings have been published in the journal Advanced Functional Materials. The paper is titled “Proteins: Materials Fabrication from Native and Recombinant Thermoplastic Squid Proteins.”