the system. The ability to control polymer solubility is of great interest in, for example, drug delivery, [4] tissue engineering, [5] or membrane technology. [6] Commonly employed thermoresponsive polymers are those that exhibit a lower critical solution temperature (LCST). [7][8][9] Such polymers are soluble at temperatures below that critical temperature, whereas they are insoluble at temperatures exceeding the LCST. [10] This change in solubility is accompanied by a conformational transformation, with a coilto-globule transition from soluble to insoluble polymers. [11] For thermoresponsive polymers endgrafted to a surface, specifically polymer brushes, this conformational change manifests itself by chains that point away from the surface when soluble, whereas insoluble chains collapse and minimize interaction with solvent molecules (Figure 1A). [12,13] This behavior results in addressable surface wettability and adhesive properties, which open the door to smart applications in cell-culture substrates, [14] temperature-dependent chromatography, [15] on-off membranes, [16] and microfluidic systems. [17] Typically, in order to obtain sufficiently high grafting densities and brush thicknesses, such polymer brushes are synthesized by surface-initiated polymerization techniques. [18] Commonly employed controlled surface-initiated polymerization procedures involve surface-initiated atom transfer radical polymerization (SI-ATRP) and surface-initiated radical additionfragmentation chain transfer (SI-RAFT) polymerization. [18,19]