Radar-based human-computer interaction when sensing through materialsAttygalle, Nuwan (Avtor) Kljun, Matjaž (Avtor) Sluÿters, Arthur (Avtor) Čopič Pucihar, Klen (Avtor) radarhuman-computer interactionsensing through materialsWe increasingly interact with computing devices that are either worn on the body (e.g. smartphones, smartwatches) or are embedded within our surroundings (e.g. smart homes, smart offices). These interactions occur through a variety of input methods, including physical buttons and knobs, mid-air gestures, touch and voice commands. With the exception of voice, these modalities require direct or near-direct physical contact with the device, typically involving line-of-sight or proximity for touch or grasp. However, interaction becomes constrained or entirely infeasible (i) when the interaction device is covered (e.g. when a smartphone is inside a pocket or a smartwatch is covered by a jacket sleeve), (ii) in sterile environments requiring separation between the user and device (e.g. when wearing personal protective equipment) or (iii) when interfaces are deliberately concealed for aesthetic, safety or functional reasons. Enabling interaction in such contexts is important to leverage the computational capabilities embedded in our environments. Yet, current technologies remain limited when interaction through occluding materials is needed. In this chapter, we examine existing research on the use of radar-based systems for interaction through materials, focusing on how materials affect system performance, principles for designing such interfaces and strategies to advance these systems.20262026-05-18 12:58:05Neznano23051sl