RheoMap: Mapping Inks, Gels, Pastes, and Slurries within a Rheological Embedding Space using Retraction-Extrusion Pressure Sensor Vectors

Viscous materials such as inks, gels, pastes, and slurries are ubiquitous across domains like food science, smart materials, digital fabrication, and the arts. However, their dynamic and unpredictable behavior—shifting over time and in response to environmental factors—poses challenges, often requiring costly equipment for accurate rheological analysis. This paper presents a low-cost, accessible sensing routine that retracts and extrudes viscous materials through an air tube, generating sensor vectors rich in rheological data. By embedding data from 26 rheologically diverse materials into a two-dimensional space, we create RheoMaps that allow for tracking material changes over time, distinguishing concentrations, and tuning rheological behaviors. These maps offer practical benefits for detecting preparation errors, guiding material design and documentation, and providing tutorial waypoints. We further discuss how this approach can be extended to extract relational insights from sensor data, improving material literacy and manipulation across a range of applications.