Self-closing and self-healing multi-material suction cups for energy-efficient vacuum grippers

While vacuum grippers offer an economical solution, the environmental impact of energy waste through their suction cups (SCs) cannot be overlooked. This waste stems from three key factors: i) air losses from idle SCs arranged in arrays, ii) inadequate sealing on target surfaces leading to air leaks, and iii) damage from sharp objects resulting in leaking perforations. To overcome these challenges, in this article, a comprehensive approach is presented that involves the development of a i) self-closing, ii) multi-material, and iii) self-healing system based on reversible elastomers cross-linked via the Diels–Alder (DA) reaction. The system incorporates a fully autonomous self-closing mechanism to prevent energy waste in SC arrays during periods of non-contact. Fluid–structure interaction simulations are utilized to analyze the design. Versatility and stability are achieved by incorporating hyper-flexible and stiff elastomers in a multi-material design, supported by covalent DA cross-links that ensure robustness through high-strength multi-material interfaces. These DA cross-links also enable self-healing capabilities, allowing the SCs to recover from macroscopic damages within 1 day at ambient conditions or in a single hour with mild heating (80–90 °C), restoring full performance. Additionally, in the article, a recycling method is introduced for multi-material SCs based on the mechanical separation of reversible polymers.