Various methods and apparatus for a wearable or insertable device (100, 200, 400, 600) with microneedles (106, 206, 306, 406, 606) that may be simultaneously used for radio frequency (RF) energy harvesting, communication, and transdermal fluid delivery and collection are disclosed. Such a device may comprise a substrate (102, 202, 302, 402, 602) that may be affixable/insertable into tissue (107, 607) of a patient, radio frequency circuitry (120, 220, 420, 620) disposed on the substrate, that may generate/process a signal with a frequency that may be modulated to carry information, and microneedles (106, 206, 306, 406, 606) extending from at least one surface of the substrate, where one or more microneedles define a micro-fluidic channel (130, 230, 430, 630) that fluidly couples the tissue with a conduit (132) of the substrate, and where one or more microneedles may be electrically coupled with the radio frequency circuitry and radiate/process electromagnetic waves based on the signal.
