Lighting the Way: Measuring Surface Tension Just Got Easier

Inventors at Oxford University have developed a new method to indirectly measure the surface tension of liquid by tracking reflected light intensity to assess the surface configuration. The procedure is reliable, repeatable, quick to set-up and use, contact-less and non-destructive.

Surface tension measurement is an important tool in the characterisation of surface-active liquids and mixtures. Although precise, traditional measuring methods suffer from several problems. With well-established methods, the volume of sample required may be many millilitres; sample recovery may be difficult or impossible; and the process may be time-consuming, manual, difficult to automate and unsuitable for hazardous samples.

By utilising a multiwell plate reader, the Oxford team has developed a novel method of measuring the surface tension of liquid. The method is based on the variation of light intensity that occurs as the angle of incidence changes for light reflected or transmitted onto a sample’s surface. This variation provides a measurement of the surface configuration, and hence surface tension, with a sensitivity comparable to conventional techniques.

The Oxford method has several commercial advantages over current techniques, including:
· Reduced sample size: microlitres vs. millilitres
· Reduced measurement time: sub-second vs. minutes per sample
· High throughput for samples arrayed on 96 well microplates
· Facile automation leading to remote handling of toxic/infectious materials
· Possible adaptation to incorporate atmospheric (pressure/gas) changes

The technology behind this method will interest the multiwell plate reader business, manufacturers of surface tension measuring equipment and the surfactant/detergent industry. The standard usage of plate readers in the biotechnology industry may be potentially improved as a result of this method.

Isis Innovation, Oxford University’s technology transfer company, has filed a patent application on this method and is currently looking for corporate partners interested in commercial development.