Waste recycling is widely used for mitigating the negative environmental impact of many technologies.
Despite this, it is heavily underutilized due to its economic limitations. Recently, additive manufacturing
presents a viable method of ameliorating this; by turning waste products, i.e., stainless steel scraps, into
a printable ink, it adds value while reducing their environmental impact. To advance printing-based
recycling, one key barrier is the poor processability of waste materials as undesired particle size and
poor colloidal stability may lead to fast aggregation and sedimentation. In this study, sedimentation
kinetics of waste metals has been studied and optimized to allow for near-room-temperature
production of printable inks from waste materials. Using these inks, the printing of strain sensors is
demonstrated for detecting minor strains from human motions.
