Soft Mechanical‐Electrical Logic Using Liquid Metal‐Filled 3D‐Printed Architectures

Rigid semiconductor‐based controllers constrain the compliance and environmental resilience of soft machines. While fluidic and pneumatic control architectures have provided softer alternatives to conventional electronics, they often lack the compactness, scalability, and integration capacity of digital systems. Here, we introduce a class of 3D‐printed soft mechanical‐electrical logic elements that integrate digital state change directly into the material architecture. The structures are fabricated from thermoplastic polyurethane/polylactic acid (TPU/PLA) parts incorporating liquid metal (LM)‐filled silicone tubes, actuated through a beam‐tooth mechanism. Depending on the configuration, the unit cells exhibit normally open (NO) or normally closed (NC) states, translating mechanical deformation into distinct electrical states. Mechanical and electromechanical characterization revealed reproducible state changes with sharp transitions. The structures’ performance under dynamic loading was tested for 100 cycles. By combining unit cells in series and parallel, we demonstrate Boolean logic primitives (AND, OR, NAND, NOR), each reproducing its truth table. The results provide a foundation for deformation‐triggered electromechanical logic in 3D‐printed soft machines, where local mechanical inputs can be converted into binary electrical states within the material architecture.