Atomic force microscopy is one of the most important tools in nanoscience. It employs an atomic probe that can resolve surfaces with atomic and subatomic spatial resolution and manipulate atoms. The qPlus sensor is a quartz-based self-sensing cantilever with a high stiffness that, in contrast to Si cantilevers, allows to oscillate at atomic radius amplitudes in the proximity of reactive surfaces and thus provides a high spatial resolution. This article reports on the development of this sensor and discusses applications in materials research.