pawH: Colorimetric pH-Sensing Toys for Non-Invasive Pet Health Monitoring

Colorimetric biosensors open up possibilities for analyte detection in pet saliva, relevant for various conditions such as bacterial infections and periodontal disease. This paper introduces pawH, colorimetric biosensors embedded in toy form factors for non-invasive pet health monitoring by displaying pH through color changes. We aim to provide easily available and non-invasive access to information typically obtained through veterinary labs. We present the fabrication process of two pet-safe toys: braided toy and ball. The toys' color changes are analyzed by a portable spectrometer, while our app converts the color readouts to estimated pH values. We performed technical evaluations for color-change response, biosensor concentration, and biosensor reusability. A user study with 11 pairs of human and canine participants was conducted to evaluate usability and pet suitability. By using pets' natural play behaviors, the toys come into contact with pet saliva, allowing for convenient and non-invasive monitoring of biochemical health in familiar settings and offering a platform for HCI implementations.