A 2-D directional air flow sensor array made using stereolithography and MEMS micro-hydraulic structures

Here we report a 2-D directional micro-hydraulic hairlike airflow sensor (HAFS), where the hair appendages are made using stereolithography for inexpensive and rapid batch fabrication. The hair structures are optimized to significantly improve the HAFS performance. The maximum measured HAFS sensitivity is 47.9 fF/(m.s^-1), a ten-fold increase over our previous uni-directional airflow sensor [1]. The new sensor dynamic range is 0-15 m.s^-1, with an extrapolated minimum detection limit of about 2 mm.s^-1, and an angular resolution of 13°.