Bread-inspired rapid gelation-induced bubble “growth-fixation” strategy to fabricate macroporous hydrogels for flexible sensors

Macroporous hydrogels (MPH) have attracted considerable interest due to their unique advantages in flexible sensing, pollutant adsorption, and tissue engineering. However, current fabrication approaches for MPH require sophisticated equipment or complex procedures and struggle to prevent structural inhomogeneity caused by bubble aging. Inspired by bread fermentation, we propose a rapid gelation method (~10 s) combining a catechol-Fe 3+ redox system with thiol-ene click chemistry, enabling “growth-fixation” of bubble during gelation to form hydrogels with sub-millimeter macropores (175 to 400 μm). The rapidly crosslinked network effectively inhibits bubble coalescence and stabilizes pore size, which can be precisely tuned by modulating the gelation process. Owing to the dynamic tuning of mechanical properties and ionic pathways by the macroporous structure, the MPH exhibits outstanding sensing performance, with a pressure sensitivity of up to −33.04 % kPa −1 , a response time of 176 ms, and a low detection limit of 0.04 kPa. This exceptional performance supports applications in motion monitoring, handwriting recognition, and Morse code decoding. This work offers a simple, efficient, and universal strategy for fabricating high-performance MPH. • Rapid gelation achieved via catechol-Fe 3+ system and thiol-ene click chemistry. • Bread-inspired bubble growth and fixation enable macroporous hydrogel formation. • Fast gelation stabilizes macropore size and morphology during curing. • Macroporous hydrogel exhibits excellent pressure sensing performance.