A micro laser Doppler velocimeter designed for a wafer-level packaging process

We develop a micro laser Doppler velocimeter (μ-LDV), designed for fabrication via a wafer-level packaging process for small size and mass production. This sensor is only 1/10,000th the volume of typical commercial LDVs. We successfully performed velocity measurement of moving solid plates and a flowing liquid with suspended particles by FFT analyzing signals obtained by our proposed μ-LDV. It can measure the velocity of any material that by itself or by constituent particles - bubbles, cells, emulsion phases, etc. - can scatter irradiated light: examples include solids like aluminum and cardboard or fluids like water, oil, and air.