  Topological superconductors are one of the most actively studied materials
these days. They are a promising candidate for hosting Majorana fermions either
on their boundaries or in vortex cores. Detecting 1D edge current around the
periphery of a 2D $p_x + ip_y$ superconductor would be a hallmark signature of
topological superconductivity, but Majorana fermions are not amenable to
electronic current measurements due to their charge neutral nature. Thermal
conductivity measurements, such as thermal Hall effect, are alternatively
proposed, but material synthesis must come first. Superfluid $^3$He-$A$, on the
other hand, is a known $p_x + ip_y$ superfluid whose edge current can be
measured with a gyroscopic technique. Here, we propose a microelectromechanical
system based gyroscope that will not only have enough signal sensitivity to
measure the edge current but also be used to observe dimensionality induced
phase transitions between different topological superfluids.
