A multiple photosensor pixel image sensor sense differentiated color components of light. The routing nodes are distributed so as to satisfy at least one inter-node separation criterion. Depending on a match of the affinity values of the data packets and the affinity values of the ports, the router forwards the data packets to selected ports. The polymers can be linked, intermixed, or a combination thereof, to one or more drugs. In another aspect, the heat patch includes an enclosure made from a gas-permeable layer and a reflective layer attached to the gas-permeable layer. In one embodiment, the retaining agent comprises a primarily hydrophobic monomer or a hydrophilic monomer.