An apparatus for delivering a substance to a surface, such as the skin of a human being, animal or other organic matter has a needle. An exemplary apparatus comprises a base; at least one first conductor; a plurality of diodes coupled to the at least one first conductor; at least one second conductor coupled to the plurality of diodes; and a plurality of lenses suspended in a polymer deposited or attached over the diodes. Power settings of beacons may be altered to change power consumption or to change a detectable range of the beacons. Further, the external contacts can be shaped by etching to have generally planar tip portions that facilitate bonding to electrodes of a supporting substrate. The bag in this embodiment holds water in one compartment and baby formula in a second compartment.