We present a low-cost and biocompatible 3D-printed fluidic device composed of a main body and two lids with membranes in between forming a tunable lens. The main body and the lids of the device is manufactured using stereolithography (SLA) technology and comprises of one or two inlets. Collagen type-I enriched Sodium Alginate membranes are sandwiched between the main body and the top and the bottom lids. A syringe pump is employed to control the amount of liquid inside the chamber, thus tuning the radius of curvature of both membranes. The device dimensions are chosen as 15 x 10 x 7 mm(3)(length x width x height), towards integration with previously developed miniaturized 3D-printed laser scanning imagers, offering focus adjustment capability. The extracted collagen, which is mixed with the membrane material, offers (1) a lens-mimicking structure, (2) biocompatibility, and (3) capability of tailoring membrane mechanical properties through adjusting collagen mass ratio. Using the manufactured device, we demonstrate focus tuning, hysteresis characterization and resolution target imaging experiments conducted at different target distances. The 3D-printed tunable lens structure is suitable for integration with a wide range of minimally invasive laser scanned imagers or ablation units presented in the literature.