Fingerprints in birefringence

(Wiley) Stimuli-sensitive materials can respond to physical forces with structural phase transitions. This also applies to biopolymer-surfactant mixtures, a study by German and Chinese scientists now reports. Surprisingly, the newly adopted phases persist after removal of the stress and can be detected by a simple optical read-out technology. Biometric fingerprint detection is an attractive application for this technology. The results are published in the journal Angewandte Chemie.