A compliant, morphing gripper for handling diverse leafy vegetables in vertical farming systems

Global food security faces growing pressure from climate change and limited resources. In land-constrained Singapore, vertical farming is expanding to improve resilience. However, this expansion has a bottleneck: many varieties of delicate leafy vegetables still rely on manual harvesting. The task is labor-intensive, and hard to scale. We address this need with a two-finger pinching gripper that has compliant, morphing fingertips. The fingertips collapse to enter narrow gaps between densely packed plants, expand to create soft contact surfaces, and reconfigure to accommodate different plant geometries. They also pinch to secure a firm grasp when needed. We validated the approach through bench tests and a trial at a local farm. The gripper consistently grasped multiple leafy-vegetable types and completed lettuce harvesting when used with a root trimmer. It maintained plant integrity and no immediate visible damage was observed. The fingertips also handled real-world variations, off-center growth, size changes, and irregular shapes, without re-tuning. These results establish a practical first step toward automated harvesting in Singapore's vertical farms and highlight next steps in perception, motion planning, and system-level line integration.