Here are some things you don’t typically associate with electricity: eggs and sperm, their meeting to conceive, whether your injuries can heal, and cancer. But in the past few decades, new tools and new insights from across a range of scientific disciplines have made it clear that electricity is involved in all of these. We are not talking about wall plug electricity here – this is bioelectricity, and it is generated in your cells. Every one of your 40 trillion cells is a little battery – and their voltage is more relevant in your biological processes than you probably ever realised. People are starting to find out how to manipulate these tiny batteries in ways that could revolutionize the way we comprehend and treat our most common maladies.