This ICNF 2017 paper by Handel examines physical 1/f noise and phase noise in piezoelectrics, MEMS resonators and sensors. The research provides comprehensive analysis of fundamental noise sources in piezoelectric devices and microelectromechanical systems used for frequency control and sensing, investigating quantum 1/f noise, thermomechanical noise, and material loss contributions, offering design strategies for minimizing phase noise in MEMS oscillators and improving sensitivity in resonant mass sensors for chemical and biological detection.