Aerosol jet printing to functionalize substrates for physiological sensors

A method of making a sensing apparatus, comprising:

• aerosol jet printing a volume of a bioactive ink on a surface of at least one electrode, the bioactive ink having a concentration of a bioactive agent adapted to interact with a biological fluid;
• forming a chamber that includes the at least one electrode arranged to expose the bioactive ink within the chamber and thereby functionalize the surface of the at least one electrode with the bioactive agent to interact with the biological fluid, as a sample under test (SUT), within the chamber;
• and
• electrically coupling the at least one electrode with sensing electronics.

An apparatus, comprising:

• a dielectric microsensor comprising a microfluidic chamber that includes a capacitive sensing structure, a volume of one or more aerosol-jet-printed bioactive agents on at least one inner surface of the microfluidic chamber to functionalize the at least one inner surface to interact with a biological fluid, as a sample under test (SUT), within the microfluidic chamber;
• a transmitter to provide an input radio-frequency (RF) signal to an RF input of the dielectric microsensor;
• a receiver to receive an output RF signal from an RF output of the dielectric microsensor;
• and
• a computing device configured to compute dielectric permittivity values for the SUT based on the output RF signal over a time interval, the dielectric permittivity values being representative of the one or more bioactive agents interacting with SUT over the time interval, the computing device further configured to provide a readout based on the dielectric permittivity values.