FabFoam: Fabricating Soft Interactive Devices with Foam Through Functional Patterning

Foam is a soft, malleable, and highly deformable substrate suited for creating interactive devices. However, prior work has mostly focused on deformation sensing by dipping foam in conductive inks. We present the first exploration of printing high-resolution functional patterns on foam, enabling multifunctional interactive devices beyond deformation sensing. Due to foam’s porosity, printing precise patterns is challenging as inks tend to seep through. Through systematic exploration, we contribute the formulation of functional inks with minimal seepage, low-temperature curing, and easy lab preparation. We then contribute the fabrication of biochemical sensors, electrotactile devices, and deformation sensors. Technical and user evaluations show FabFoam’s glucose sensors detect sweat glucose at an activation voltage of 0.45 V, with a sensitivity of 2.74 µA/µM and a resolution of 4.67 µM. FabFoam tactile devices deliver perceivable electrotactile feedback, and our technique supports a minimum patterning resolution of 0.5 mm spacing and 1 mm trace width across foam types. We present a set of application scenarios demonstrating the versatility of FabFoam.