Laser‐micromachined cellulose acetate adhesive tape as a low‐cost smart material

An off‐the‐shelf, moisture‐responsive, acetate‐backed adhesive tape is investigated as a commercially available smart material for fabricating low‐cost, multifunctional, humidity‐responsive millimeter‐scale structures. Laser ablation is used for cutting and thinning‐down the tape to enhance its response. Water‐submerged cantilevers show a radius of curvature of 3 mm or lower (for laser‐thinned cantilevers). Additionally, their humidity response is a function of the angle between the longitudinal axis of the cantilever and polymer orientation. A cut angled at 80° with respect to this orientation results in a tip rotation of up to 25°, enabling the formation of bending cantilevers with twisting behavior. The tape cantilevers are further functionalized with magnetic nanoparticles and used to create four‐finger grippers that close underwater within minutes and can sample 100 µL of liquid. A cyclic humidity monitor is also fabricated using a tape strip that walks unidirectionally on a ratchet‐shaped surface upon exposure to humidity variations. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51, 1263–1267