:In　this　paper,　we　revealed　the　sensitive　mechanism　of　a　MEMS　z　axis　fluidic　gyroscope　based　on　the　open　airflow　channel.　The　3D　transient　finite　element　analysis　method　based　on　fluid-structure　interaction　was　used　to　calculate　the　airflow　field　inside　of　the　sensitive　element　and　the　numerical　model　is　established.　The　calculation　and　test　results　indicated　that:　there　was　an　open　airflow　channel　inside　of　the　sensitive　element,　and　two　inlets　and　one　outlet　were　set　up.　The　airflow　was　driven　by　the　piezoelectric　pump　and　entered　from　two　inlets　and　was　converged.The　airflow　from　the　nozzle　created　a　jet-sensitive　body　in　the　jet-sensitive　chamber　and　flew　out　of　the　outlet.At　the　static　state,　the　jet-sensitive　bodywas　symmetrically　distributed　relative　to　the　hotwires　r　1　and　r　2　,　the　speed　gradient　β　x　between　the　hotwires　r　1　and　r　2　as　the　two　arms　of　bridgewas　zero.　Therefore,　the　bridge　is　balanced　and　output　voltage　is　zero.　When　the　angular　velocity　was　applied,　the　jet-sensitive　body　was　deflected　along　z-axis　under　the　action　of　the　Coriolisforce;　the　jet-sensitive　body　was　no　longer　symmetrically　distributed　with　respect　to　the　hotwire　r　1　and　r　2　,　thus　the　velocity　gradient　β　x　between　r　1　and　r　2　increased　with　the　increase　of　the　angular　velocity.　Additionally,　at　the　same　condition　of　other　materials　and　result　parameters,　the　resistance　value　of　two　hotwires　changed　asymmetrically　because　of　the　asymmetric　heat　exchange　between　r　1　and　r　2　and　sensitive　jet　flow.Therefore,　the　bridge　was　not　balanced　anymore　and　output　an　unbalanced　voltage　proportional　to　applied　angular　velocity.　In　the　input　range　of　±120　(°)/s,　the　sensitivity　of　gyroscope　was　2.0　μV/[(°)·s　-1　],　and　simultaneously,　the　nonlinearity　was　better　than　0.5%.　In　addition,　the　power　consumption　was　5.2　mW,　the　resistance　value　R　of　hotwire　was　3　Ω　and　the　temperature　coefficient　of　resistance　of　hotwire　was　2　600/℃.There　was　a　directional　flow　between　two　inlets　and　outlet　inside　of　the　sensitive　element　of　this　open　z-axis　gyroscope　based　on　MEMS,　without　circulation　airflow.　The　sensitive　element　was　simple　in　structure.　©　2018,　Editorial　Department　of　Journal　of　Piezoelectric　and　Acoustooptic.　All　right　reserved.