Physicists have developed a way to help structurally modify spider silk fibre and microweld it with various metals and carbon-based materials1 — a method that could be useful for making various spider-silk-based microstructures such as ultrasensitive sensors.
Spider silk is a tough and lightweight biomaterial. However, existing techniques that modify silk fibres using ultraviolet light can degrade the fibre structure, robbing it of its function and strength.
To safely modify spider silk fibre at nanoscale, scientists from the Indian Institute of Science Education and Research Mohali devised a method that first inflated silk fibres with a stream of photons and then ablated them with extremely short pulses of laser.
Their method helped convert silk fibres into periodic patterns such as nanotips, cuts and grooves that remained stable in air and in a vacuum.When a silk fibre was bent using short pulses of laser, it retained surface smoothness without any sign of microscopic voids or cracks.
Using the method, it was possible to make a solenoid, a microspring, a microlens and knotted bundles from silk fibres. These silk structures can find applications as ultrasensitive force sensors that can detect minute force exerted by electromagnetic radiation pressure.
This optical approach could potentially help fabricate diverse topological microstructures such as Mobiüs strips, chiral helices and silk-based sensors that are driven by light in air or on a water surface, the researchers say.