Due to the rapid development on MAVs and small UAVs, low Reynolds number airfoils are becoming increasingly important in aerodynamics. The generation of laminar separation bubbles at low Reynolds number due to adverse pressure gradients presents a problem for the flight characteristics since vortex shedding causes low frequency variations in L/D. Several different approaches have been investigated for active flow control to reduce the flow separation and improve L/D performance. We use an adaptive wing, an airfoil which will change its shape based on the prevailing flow conditions to actively control separation. The shape change is accomplished by using a series of piezoelectric actuators mounted on a modular wing with a base profile of a NACA 4415. Smoke wire flow visualization in the wind tunnel has given us preliminary result on the possibility of controlling the flow separation. In this presentation, particle image velocimetry (PIV) measurement data obtained in a wind tunnel will be presented and discussed. PIV measurements are collected at 3 Reynolds numbers (25k, 50k, and 100k) and two angles of attack (0 and 9 degrees).