(A) An overview of emerging mounting locations and form factors for medical wearables. (B) Images of five representative form factors: a miniaturized device on a fingernail (13), a holey device on the skin (42), a binodal pair of skin-like devices on the hand, a soft microfluidic on the skin (17), and an instrumented contact lens on the eye (27). Photographs in (B) are reproduced with permission from (13, 17, 27, 42).