A heat exchanger with multi-flow capabilities includes a pair of intermediate tanks located between a pair of header tanks. The device comprises a housing attachable to the article, the housing defining a storage chamber with a storage chamber opening at one end. A server is then accessed to read a configuration file of the SIP endpoint device. A transparent conductive film is formed on an upper surface of the CF substrate. A processor determines a concentration of ions in the extracellular fluid as a function of the response. Other examples and related methods are also disclosed herein.