Future Proof remembers the good old days when visible brown stains of nicotine were an aerostructures specialist's dream.
One only has to recall China Airlines Flight 611 where one of the more surprising features of the investigation into metal fatigue was revealed by the tell-tale nicotine stains deposited by the accumulated smoke from years of furious tabbing.
According to Chemistry World magazine, time and tobacco tidemarks have moved on and fluorescent proteins are now being touted as one of the chief tools in the identification of microscopic cracks and damage in polymer materials, allowing them to be monitored to prevent failure in load-bearing applications.
Doug Clark and colleagues from the University of California in Berkeley encased two fluorescent proteins inside two halves of a protective protein shell and embedded them into a polymer matrix. How far the two halves of the shell are pulled apart affects the fluorescence of the two proteins, so monitoring the fluorescence can indicate where the polymer was being deformed or cracked.
The protein shell that the team used is called a thermosome as it comes from the microbe thermoplasma acidophilum, which thrives in hot, acidic conditions where normal proteins quickly lose their function. The team grow the proteins in engineered E. coli bacteria, so Clark is confident that they represent a cost-effective and green way of making nanosensors.
