Johns Hopkins University researchers used a light to restart mouse hearts, which works due to embedded light-sensitive proteins rather than the volts of power currently used for similar jobs. Human trials for patients at risk of arrhythmia are still at least five years away.

If you're interested in the How It's Made video, that's here and the mock Apple ad from Conan is here. As always, please share any interesting tech or science videos you find by using the #ICYMI hashtag on Twitter for @mskerryd.