3D-Printable high-mixed-conductivity ionogel composites for soft multifunctional devices

[Display omitted] •3D-printable high-mixed-conductivity ionogel/SWCNT composites were developed.•Ionic liquids enabled high-quality, stable, photopolymerizable SWCNT dispersions.•Vat photopolymerization allowed high-resolution fabrication of the composites.•High ionic (1.02 mS/cm) and electronic (1.82 mS/cm) conductivities were achieved.•High-performance micropyramid multifunctional devices were precisely 3D-printed. Multifunctional components are pivotal for the physical intelligence of synthetic robots, mirroring the multifaceted roles seen in natural organisms. Achieving such complexity is challenged by the rigidity and the intricate assembly required of monofunctional parts and by the difficulty of designing materials that respond distinctly to multiple stimuli. A key challenge in developing multifunctional devices is to co-evolve intrinsically multistimuli-responsive materials with their fabrication methods. In this context, materials with mixed ionic-electronic conductivity (MIEC) stand out, as their dual conductivity enables the concurrent processing of diverse signals. However, the lack of precise fabrication techniques has restricted the full exploitation of MIECs in creating multimaterial, complex-shaped, hierarchically structured multifunctional devices. We introduce high-conductivity soft ionogel/single-walled carbon nanotube (SWCNT) MIEC composites (ISMCs), 3D-printed in high resolution using vat photopolymerization (VPP). These composites are showcased in multifunctional pressure–temperature sensors capable of detecting pressure thanks to a SWCNT network and sensing temperature in a broad range with a high sensitivity owing to the ionic conductivity of an ionic liquid (IL). We suggest that the high electronic (1.82 mS/cm) and ionic (1.02 mS/cm) conductivities, combined with precise, single-step VPP 3D-printing, lay the groundwork for versatile, soft multifunctional devices for a wide range of applications.