Abstract: In this talk I will discuss my group’s progress toward a new class of classical microwave frequency phononic devices created by heterogeneously integrating semiconductors and piezoelectric materials. The combination of these materials allows for active and nonreciprocal phononic circuit functionalities to be achieved on a single chip, such as amplifiers, isolators, circulators, mixers, and switches. Combined with their ability to perform narrow-band filtering and duplexing, these phononic circuits pave the way for a new era of radio frequency signal processing on a chip. Then I will describe our recent theoretical and experimental work on giant phononic nonlinearities mediated by electron-phonon interactions and how these nonlinearities may be leveraged to provide new functionality for quantum information processing with phonons.