The well-known triboelectric effect refers to the charging of solid surfaces upon mechanical contact. This ubiquitous phenomenon has macroscopic consequences, ranging from the mundane to the fundamental (e.g., tribocharging promotes dust aggregation, which may have played a key role in the early stages of planet formation). However, the origin of this surface charging remains poorly understood, and has been variously attributed to the transfer of minute quantities of electrons, ions or material between surfaces. Interestingly, water - through the exchange of protons and hydroxide ions - has been put forward as a potential key player in electrification, an exciting hypothesis that we aim to test. The aim of this internship is to explore the fundamentals of solid triboelectrification, building on two complementary approaches currently being developed in the group, based on electrostatic spatio-temporal charge mapping and nanometrically resolved surface force measurements.