Is this interactive avatar the face of the future?

A virtual "talking head" which can express a range of human emotions and could be used as a digital personal assistant has been developed by researchers in Cambridge.

According to its designers, Zoe is the most expressive controllable avatar ever created, and could be used on mobile phones or tablets.

The result of several days filming with an actress, the face can display emotions such as happiness, anger and fear, and changes its voice to suit the user's preference.

Rory Cellan-Jones went to meet the team behind Zoe and find out how they make it work.