The ever-increasing need to miniaturise the methods for handling and reacting substances (see nanotechnology) has led to the development of  chips etched with channels and reservoirs which can be used to control the flows of separate fluids and their reactions with each other. The chips can be based on materials like silicon, quartz, glass, or  silicon rubber. The chip can be used as a flow injection manifold. In MS, the fluid flows can be made to exit though a small aperture and, with the application of an appropriate electrical charge, be ionised by a nanoelectrospray process.