LAUSR

Mismatched deformation in a bilayer composite with rigid coating on soft substrate results in complex and uniform topographic patterns, yet it remains challenging to heterogeneously pattern the upper coatings with various localized structures. Herein, a heterogeneous, 3D micro-structure composed of Ti3C2Tx titanium carbide (MXene) and single-walled carbon nanotube (SWNT) was fabricated using a one-step deformation of a thermally-responsive substrate with designed open holes. The mechanically deformed SWNT-MXene (s-MXene) structure was next transferred onto an elastomeric substrate, and the resulting s-MXene/elastomer bilayer device exhibited three localized surface patterns, including isotropic crumples, periodic wrinkles, and large papillae-like microstructures. By adjusting the number and pattern, the s-MXene papillae arrays exhibited superhydrophobicity (> 170°), strong, and tunable adhesive force (52.3-110.6 µN), and ultra-large liquid capacity (up to 35 µL) for programmable microdroplet manipulation. The electrically conductive nature of s-MXene further enabled proper thermal management on microdroplets via Joule heating for miniaturized antibacterial tests. The s-MXene papillae were further fabricated in a piezoresistive pressure sensor with high sensitivity (11.47 kPa-1). The output current changes of s-MXene sensors were highly sensitive to voice vibrations and responded identically with pre-recorded profiles, promising their application in accurate voice acquisition and recognition.