A chemical composition, comprising: one or more bridged polycyclic compounds, wherein the chemical composition is suitable to form an antimicrobial coating over at least a portion of a surface, wherein at least one of the bridged polycyclic compounds comprising at least two cyclic groups, wherein at least two cyclic groups are defined in part by quaternary ammonium moieties, and wherein the bridged polycyclic compound comprises a general structure: wherein each R 1 is independently an alkyl-aryl group, a substituted alkyl-aryl group, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, N, N + R 3, a heterocycle group, or a substituted heterocycle group; wherein each R 2 is independently an alkyl-aryl group, a substituted alkyl-aryl group, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a heterocycle group, a substituted heterocycle group, a covalent bond, or an alkene; wherein each R 3 is independently an alkyl-aryl group, a substituted alkyl-aryl group, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a heterocycle group, a substituted heterocycle group, an alkene, an ether, a PEG, or a PEI; wherein each R 4 is independently an alkyl-aryl group, a substituted alkyl-aryl group, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a heterocycle group, a substituted heterocycle group, an ether, an amide, an alcohol, an ester, a sulfonamide, a sulfanilamide, or an alkene; wherein Z comprises at least one bridge, wherein at least one of the bridges is - R 2 - N + R 3 2 - R 4 - N + R 3 2 -R 2 -, - R 2 - NR 3 - R 4 - N + R 3 2 - R 2 -, - R 2 - NR 3 - R 4 - NR 3 - R 2 -, or - R 2 - N = R 4 = N - R 2 -, and wherein each bridge independently couples R 1 to R 1; and wherein X comprises one or more negatively charged counter ions. one or more bridged polycyclic compounds, wherein the chemical composition is suitable to form an antimicrobial coating over at least a portion of a surface, wherein at least one of the bridged polycyclic compounds comprising at least two cyclic groups, wherein at least two cyclic groups are defined in part by quaternary ammonium moieties, and wherein the bridged polycyclic compound comprises a general structure: wherein each R 1 is independently an alkyl-aryl group, a substituted alkyl-aryl group, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, N, N + R 3, a heterocycle group, or a substituted heterocycle group; wherein each R 2 is independently an alkyl-aryl group, a substituted alkyl-aryl group, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a heterocycle group, a substituted heterocycle group, a covalent bond, or an alkene; wherein each R 3 is independently an alkyl-aryl group, a substituted alkyl-aryl group, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a heterocycle group, a substituted heterocycle group, an alkene, an ether, a PEG, or a PEI; wherein each R 4 is independently an alkyl-aryl group, a substituted alkyl-aryl group, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a heterocycle group, a substituted heterocycle group, an ether, an amide, an alcohol, an ester, a sulfonamide, a sulfanilamide, or an alkene; wherein Z comprises at least one bridge, wherein at least one of the bridges is - R 2 - N + R 3 2 - R 4 - N + R 3 2 -R 2 -, - R 2 - NR 3 - R 4 - N + R 3 2 - R 2 -, - R 2 - NR 3 - R 4 - NR 3 - R 2 -, or - R 2 - N = R 4 = N - R 2 -, and wherein each bridge independently couples R 1 to R 1; and wherein X comprises one or more negatively charged counter ions.