We propose the development of a basic module for a novel nanowire-based nanoelectromechanical device, which will require the mechanical coupling of nanowires to an AlGaN/GaN heterostructure containing a polarization-induced 2D electron gas. The deflection of freestanding nanowires in a streaming liquid causes an additional strain in the AlGaN barrier which leads to a change in the resistance of the 2D electron gas. The basic structure, underlying theoretical considerations and first steps towards the realization of this new sensor concept are presented.