Noninvasive characterization of glucose aqueous solutions based on continuous-wave photoacoustic techniques: A phantom-based approach

This paper describes the design, fabrication, and testing of a fluidic cell, i.e., the phantom, dedicated to the noninvasive characterization of aqueous solutions based on continuous wave photoacoustic (CW-PA) protocols. The proposed fabrication method relies on the patterning of three PMMA plates with a laser cutter, which are bonded together with double-side tape for flexibility in the design and fast prototyping. First, PA measurements were performed and acoustic resonance was obtained at several frequencies whatever the cavity size. Then, measurement of sensor response to glucose concentration according to the two CW-PA-based protocols developed previously and for various cavity sizes revealed linear dependences, but the slopes consequently differ from the one obtained with a standard detection cell. In addition to demonstrating the concept of phantom-based measurements, this new approach shows how the heterogeneous characteristic of the phantom affects the two measurement protocols in very specific ways.