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A D V A N C E D M A T E R I A L S & P R O C E S S E S | O C T O B E R 2 0 1 7 3 4 salinity of the water, amount of nutri- ents, and intensity of solar radiation, as biofouling activity increases with rising temperature [7] . Thus, biofouling of submerged structures and marine vessels is expected to increase with a global rise in temperature due to cli- mate change. Historically, antifouling methods included coatings containing heavy metals such as lead and mercury, later banned due to environmental risks [9] . Tributyltin (TBT) is a well-established example of a self-polishing copolymer technique using heavy-metal toxicity to deter marine organisms, which was banned in 2003 [9] . More recent develop- ments in antifouling coatings include nontoxic coatings. The majority of tra- ditional antifouling coatings are regu- lar paints, often consisting of enamels, varnishes, undercoats, primers, seal- ers, and fillers. Antifoulants are inject- ed as one of the additives incorporated during the application of topcoat paint and function by leaching antifoulants during the life of the coating, which spans two to five years [3] . Copper and biocides are also antifoulants, but bio- cides are under scrutiny by various sci- entific panels due to their toxicity to non-targeted organisms [3] . Foul-release coatings (FRCs) are another type of antifouling system, which function on the principle of low surface energy to minimize the or- ganism’s ability to develop a strong interfacial bond with the material sur- face. Coating smoothness at the molec- ular level dislodges organisms from the surface when the vessel is moving be- yond a critical velocity [3] . However, such coatings are not effective for station- ary submerged structures and docked vessels. The nonstick surfaces facilitate the removal of biofilms and organisms through shearing of the interfacial bond between organism and surface due to tensile stresses under their own weight . FRCs are categorized as fluoropolymer- and silicone-based coatings. FRCs are also ineffective in the case of early stag- es of biofilm formation and small bio- foulers like diatoms [3] . Nature is an inspiration to look for solutions. A biomimicry approach has been explored for antifouling sys- tems [3,10,11] . Marine organisms have both physical and chemical methods to pro- tect themselves from biofouling. For example, the mold of crab, mussel, lo- tus leaf, whale, and shark skin are im- mune to biofouling. Studies inspired by these examples [10-15] have not yet re- sulted in functioning systems due to cost and limited lifetime. A more real- istic biomimetic approach could result in potentially better antifouling solu- tions inspired by the combination of an organism’s chemical and physical anti- fouling attributes. Biocement ground improvement method . Coastal infrastructure and prime real estate along the coastlines are anticipated to be most affected by SLR. Erosion of the base and support structures of infrastructure due to more frequent flooding and SLR can under- mine the structural integrity of coastal structures including bridges and build- ings. The soil around the base can lose its strength due to increased wave ve- locity and splash zones. Further, soil stability in coastal areas is vulnerable to liquefaction due to SLR. Strengthening of soil—or ground improvement—is often desired for the stability of any structure before con- struction. Industrially, surface soil stabilization is often achieved using ap- proaches like mechanical compaction, installing sheets or piles, and mixing the soil with lime or cement (chemical method). Mechanical compaction tech- niques usually require large machinery and energy sources. These processes are expensive, increasing project costs. Figure 5 shows a schematic of a typical industrial scale, cement-based ground strengthening process. It usually begins with drilling and simultaneous pump- ing of water. The cement-based mixture is injected through a pressurized mech- anism and then spread. Similar steps are repeated for application to a wid- er area and to provide more stability (Fig. 5). These processes often result in disturbance to urban infrastructure and also have an environmental impact due to the chemicals involved. Hard- ened cement also reduces soil permea- bility, thereby affecting the percolation of rainwater to the groundwater table. Consequently, conventional methods have limitations and more environmen- tally friendly choices should be used. A microbial-induced carbonate precipitation (MICP)-based ground im- provement method was recently de- veloped [17] based on the ability of a microorganism to catalyze a chemical reaction to produce minerals such as CaCO 3 . For example, Sporosarcina pas- teurii (DSM33/ATCC 11859) induces hy- drolysis of urea, producing ammonium and carbonate ions. In the presence of a supersaturated calcium solution, car- bonate ions react with calcium ions to produce CaCO 3 . Microbial precipitat- ed CaCO 3 functions as cement material Fig. 5 — Schematic showing steps and process of cement-based ground improvement method [16] .