It's our 4th anniversary this week, coinciding with Rafe's birthday, so the team take time-out to celebrate with cake.
When they're done with that, Rafe dons his lab coat and schools the team in wonderful - and frequently rare - materials that go into making smartphones and tablets. The team discuss the issues with using such materials and the ways in which they contribute to advances in screens, batteries, components and protective coverings.
There's also - briefly - some singing... Sorry about that.