In this work, spider dragline silk is introduced for the first time as a new biomaterial for Micro-Electromechanical Systems (MEMS).
Spider silk, Micro-Electromechanical Systems (MEMS)
Spider silk is the silk produced by spiders to spin their webs. Scientists have long been curious about the properties of this material. Research into it has led to the discovery that this silk is incredibly tough and its tensile strength is equated to that of steel. When steel and spider silk are at the same diameter, spider silk has been found to be five times stronger. It is also stronger than Kevlar, which is the toughest man-made polymer.
Spider silk is finer than a human hair. The Golden Orb-Weaving spider is known to have the toughest silk. It is known as dragline silk and has a golden hue to it. Spider silk is very elastic and can be stretched 2 to 4 times of its original length. Being tougher and more elastic than silk from the silkworm, it has a wider range of applications. Unfortunately, harvesting it is a tough task as spiders produce very small quantities at a time. This has been an impediment to the progress in this field.
The composition of spider silk is basically protein. It has a complex structure, which is not solely dependent on how it is made. The weaving of the spider web also has an effect on the final composition of this silk.
Researches on spider silk
Scientists are working on ways to duplicate spider silk so that it can be used extensively. Spider silk can be used to create an artificial skin for burn victims, to make artificial ligaments, manufacture bandages that can promote healing, as sutures during surgery, for making gentle airbags in automobiles etc.
The ability of spider silk to stop bleeding and promote healing of wounds makes it an attractive material for biomedical applications. The biodegradable and biocompatible property of spider silk makes it an attractive option for creating artificial skin. The presence of vitamin K and the antiseptic property of spider silk effectively helps in blood clotting.
Spider silk has the ability for high contraction, which is also called a super contraction. It also has cyclical contraction where it contracts just a little, say 1-2%. In the field of medicine, this can be used to create artificial muscle, which could be used in micro-electromechanical systems (or MEMS). The silk will have to be gathered from a spider, which is not a viable option. Scientists have been trying for years to recreate spider silk with little success.
If successful, synthetic spider silk can be extensively used to make safety equipment, sporting goods, and in several medical practices in the future. We may be getting close to that future but the best version of this silk will still remain the one nature makes.