SLICE: Discarded Tennis Balls Reconstructed as Wearable Shoes

Designer Soroosh Riazi Isfahani has developed SLICE, a footwear project that transforms discarded tennis balls into wearable shoes. The process involves slicing the balls into repeatable components using custom 3D-printed guides, which hold each ball in place while a blade cuts along a set path. The resulting curved bands and cup-like sections are then assembled around the foot, with black stitching and cord connecting the pieces. The fluorescent yellow skin, complete with white seams and printed logos, remains visible, preserving the ball's original identity. Isfahani initially experimented with shredding and mixing tennis ball particles with natural rubber for outsoles, but found that this erased the ball's beneficial properties. Slicing instead keeps the composite intact, leveraging the ball's geometry and texture. The project responds to the significant waste stream of tennis balls, with an estimated 400 million produced annually, few of which are recycled. Existing recycling methods often grind balls into granules, but SLICE offers an alternative by using the ball's structure directly. The prototype has been photographed on a tennis court, indicating it is wearable, though its long-term performance remains untested. SLICE is a 2026 James Dyson Award entry, and while the current process is experimental, it suggests potential for larger-scale manufacturing with faster cutting and sorting systems.