Steve Caplin explains why Tesco is tattooing avocados. Japanese scientists believe people will soon be able to grow new teeth. There's a robot seed-planter taking its inspiration from wild oats. A 9-seater electric plane can take off and land on a football pitch. A new Chinese hybrid car has a massive range and a minimal price, in China at least. Cambridge scientists have been studying how people make use of a third thumb. There's a crowd-funded pet monitoring camera which can tell if the animal is poorly. Bringing the internet to a remote Amazon tribe has caused problems. And in Dubai, there's a proposal to build skyscrapers 1km high.