Abstract: In one embodiment, an apparatus includes first and second via structures in a substrate. Each via structure defines a coupling element that extends from the via structure toward the other via structure such that the coupling elements capacitively couple with one another in an area between the first and second via structures.

Abstract: Scanning probe microscopes include a probe tip coupled to a tuning fork or other acoustic resonator so as to apply a shear force when contacted to a specimen surface based on an applied acoustic signal. A secondary ultrasonic transducer is in acoustic communication with the specimen and a resonant structure. Probe tip-specimen displacement can be detected based on whispering gallery mode ultrasonic waves in the resonant structure using the secondary transducer, and such displacements maintained using feedback control based on whispering gallery mode acoustic wave magnitude.