An important challenge in ubiquitous computing (ubicomp) is to create techniques that allow people to seamlessly and naturally connect to and interact with the increasing number of digital devices. I propose to leverage the knowledge of people’s and devices’ spatial relationships – called proxemics – in ubicomp interaction design. I introduce my work of proxemic interactions that consider fine-grained information of proxemics to mediate people’s interactions with digital devices, such as large digital surfaces or portable personal devices. This research includes the design of development tools for programmers creating proxemic-aware systems, and the design and evaluation of such interactive ubicomp systems. Keywords Proxemics, interaction, user interfaces, ubiquitous computing, digital interactive surfaces, digital devices ACM Classification Keywords H.5.2 [Information interfaces and presentation]: User Interfaces: Input devices and strategies. General Terms Human Factors, D...