We design and fabricate integrated mechanical devices. These include various types of acoustic and optomechanical resonators, phononic waveguides, and piezoelectric transducers and actuators. This toolbox of mechanical components has allowed us to realize complex devices. One such application is microwave-to-optical frequency conversion where it is required to engineer a piezoelectric transducer, a phononic waveguide and an optomechanical cavity that are interconnected.
Inspired by integrated photonics, we also fabricate phononic integrated circuits which guide acoustic waves on a chip. In such circuits, we can for example realize compact microwave filters and study nonlinear acoustic effects which are enhanced by the small acoustic mode volume. Since acoustic waves propagate 100,000 times slower than light, they are ideal for implementing delay lines operating at microwave frequencies for applications in communications, sensing, and quantum technologies. It is also important to be able to drive the acoustic waves and launch them into the waveguides. We typically convert microwaves into acoustic waves using piezoelectric transducers. One aspect of our research is to design and fabricate transducers that are as efficient as possible.