Microneedle thermal flow sensor

We present a microneedle thermal flow sensor for measuring low speed liquid flows. Even though many types of liquid flow sensor have been developed, they are limited to flow measurements only in specific closed systems. However, our needle-shaped flow sensor can be flexibly applied to variety of fluids. To predict sensor operation, we conducted thermal transport simulation based on multi-physics modeling comprising heat transfer in fluids, laminar flow, and joule heating. Our measurement system consists of needle shape sensor, fabricated by deep reactive ion etching (DRIE) process, and microprocessor-based control system combined with voltage regulator and amplifier.