Figure 1. Rationally designed crosslinker architecture enables logic-based material degradation.

(a) The YES-gate material crosslinker contains a single stimuli-labile moiety (red). Presence of the corresponding chemical input cleaves this moiety, breaking covalent linkage between molecular endpoints (pink) to yield material degradation. Each region of the Venn diagram corresponds to a unique combination of inputs and indicates whether the material is expected to degrade (colored) or remain intact (white). (b) The OR-gate crosslinker contains two different stimuli-labile moieties (red and blue) connected in series. The presence of either relevant input cleaves the crosslinker, resulting in material degradation. (c) The AND-gate crosslinker contains two different stimuli-labile moieties (red and blue) connected in parallel. The presence of a single programmed input cleaves one linker arm but does not fully sever the crosslink, leaving material crosslinking density and mechanical properties unchanged. (d) Logic gates can be hierarchically combined to generate higher-order logical responses. Seventeen unique materials can be generated by combining three logic gates (YES, OR, AND) with three distinct inputs. (e) Reactions depicting cleavage of the stimuli-labile groups: disulfide bonds (orange) are reduced into free thiols, the proteolytically sensitive peptide sequence GPQG↓IWGQ (green) is enzymatically cleaved by MMP, and the oNB moiety (purple) undergoes photoscission in the presence of near-UV light (λ = 365 nm).