The way we control the speed of fan motors or pump motors has tremendously changed in the past two decades with the introduction of variable-frequency drives (VFDs), aka variable-frequency controllers ...

(a) Schematic of frequency multiplexing achieved by comining phase profiles derived from plate theory with wavefront-engineered phase control. (b) Photograph of the fabricated elastic metasurface that ...

The evolution of precision clocks. The tradeoffs between MEMS vs. crystal oscillators. The manufacture and cost issues involved. Almost every electronic device you can imagine depends on a precision ...