Mechanical pulling of adhesive tape creates radicals on the tape's surface. These radicals are capable of reducing metal salts to the corresponding metal nanoparticles. In this way, the mechanically activated tape can be decorated with various types of nanoparticles, including Au, Ag, Pd, or Cu. While retaining their mechanical properties and remaining "sticky," the tapes can exhibit new properties derived from the presence of metal nanoparticles (e.g., bacteriostaticity, increased electrical conductivity). They can also be patterned with nanoparticles only at selective locations of mechanical activation.D eposition of nanoparticles (NPs) on surfaces is important in a range of technologies, leading to the formation of antibacterial films on clothes and kitchen appliances, 1 medical devices, 2 electronic components, 3 and many more. Other than physisorption, the formation of such NP coatings requires chemical activation of the target surface, enabling the formation of covalent bonds harboring the NPs. Here we take a conceptually different route to surface activation and NP deposition, namely, via mechanochemical treatment. We have recently shown that when contacted and then separated, polymeric surfaces develop both surface charges and radicals. 4 These species form as a result of bond breakingheterolytic and homolytic, respectivelythat occurs when the materials are being separated. In the present work, we applied these phenomena to popular adhesive tapes, which, when pulled, develop enough mechanoradicals to drive radicalic reduction of metal salts to their nanoparticulate forms. By this route, we were able to deposit a range of different types of NPsfrom antibacterial silver 6 to antifungal copper 7 on the "sticky" side of the tape or only on its patterned fragments. The tapes covered with NPs retain their adhesive properties while gaining new ones, including increased electrical conductivity or bacteriostaticity. The mechanochemical activation by simple pulling provides a straightforward yet previously unexplored means of surface activation of polymer-based adhesives.Our material of choice was a commercial Scotch adhesive tape (Figure 1a), the same as the one underlying the Nobelwinning work on graphene 8 and several other applications such as triboluminescence, nondamaging isolation of plant tissues, and quantification of material adhesion. 9 Although we used the Scotch tape in most of the experiments described below, we also verified the formation of NPs on tapes of different compositions and from different suppliers (e.g., VIBAC 2″ clear packaging tape).From the standpoint of mechanochemistry, Scotch tape is convenient because the polyacrylic adhesive it contains is in conformal contact with the tape's nonsticky polyethylene-based side. When peeled off with typical speeds measured in cm/s, the separation of the adhesive results in heterolytic bond breaking and contact charging characterized by a net/ macroscopic charge on the order of few nC/cm 2 , as measured using an in-house-made Faraday ...