Forensics

Liquid Fingerprinting Technology will Aid First Responders

A new technology, Watermark Ink (W-INK), can distinguish liquids by their surface tension. The technology that can perform instant, in-field characterization of the chemical make-up and material properties of unknown liquids could aid first responders and improve plant safety.

Validere, a new company cofounded by Harvard scientists and engineers, will commercialize the new technology. Validere aims to develop the W-INK into a pocket-sized device that could be used by first responders to quickly identify chemical spills, or by officials to verify the fuel grade of gasoline right at the pump.

Developed in the Harvard laboratory of Prof. Joanna Aizenberg, the W-INK concept exploits the chemical and optical properties of precisely nanostructured materials to distinguish liquids by their surface tension.

Akin to the litmus paper used in chemistry labs to detect the pH of a liquid, the detector changes color when it comes in contact with a liquid with a particular surface tension. The color-changing strip can be programmed to respond precisely to the unique surface tension exhibited by any liquid of interest.