How facial expressions help robots communicate with us

A wrinkled nose, raised eyebrows, a frowning mouth--all can say a lot without uttering a single word. Facial expressions are the closest thing humans have to a universal language, and it could change our relationship with androids and other human-like robots. There are a lot of us. But no matter where we come from or the languages we speak, by using these we can still connect with other humans. There are so many purposes of facial expressions.