9:45 AM - 10:00 AM
▼ [20a-E214-3] A Transparent Flow Velocity Sensor of Ultra-thin Glass Sheet Fabricated by Femtosecond Laser Processing
Keywords:microfluidic device, laser application
Flow velocity measurement in microchannel is an important issue because the flow velocity plays a crucial role in flow cytometry and cell/particle sorting. Despite its importance, the performance is restricted by the limited space of microchannel. The conventional thermal sensor with heating might damage biological objects flowing in microchannel and mechanical sensor with complicated structure is difficult to fabricate and it is challenging to place the sensor at desired positions. This study proposes a transparent and durable flow velocity sensor made of ultra-thin glass sheet by femtosecond laser processing that is simple in structure and less influence to flow in microchannel. The detection system consists of the proposed sensor and a laser position detection system. For flow velocity measurement, the reflected laser spot is located at the center of the two-segmented photodiode (TSP) on the condition without flow in the microchannel. When there is flow in the microchannel, the reflected laser spot moves on the TSP with deformation of the sensor. The temporal position shift of the laser spot is recorded to quantify the flow velocity. Besides, we find that the sensor vibrates periodically under the influence of flow and the vibration frequency increases with the increase of flow velocity which will be further explored.