3D printing aqueous Ti₃C₂T_x inks for MXene-based energy devices

The miniaturization of microenvironments and increasing demands on modern-day electronics have reinvigorated the search for new candidates to meet these needs. The MXene (M_n+1X_nT_x) family has been seen as the next major player in the field of microelectronics due to the unique combination of superior properties. Incorporating microelectronics in micropatterned structures via simple, cost-efficient processing also increases the possibilities of using them in smart devices and microsystems. This short communication reports the nanoparticle synthesis, suspension processing, and 3D printing of a titanium carbide (Ti₃AlC₂)-based MXene, with the derivation from its elemental powders. More importantly, the in situ etching method was employed to create a multi-layered MXene (Ti₃C₂T_x), showing high efficiency in generating delaminated Ti₃C₂T_x nanosheets. Afterward, water-based Ti₃C₂T_x inks were examined in varying (i.e., 30 mg mL⁻¹, 50 mg mL⁻¹, 100 mg mL⁻¹, and 200 mg mL⁻¹) concentrations for optimized rheologies. An ink-writing-based 3D printing method was then used for micropatterning MXene thin-layers on glass or polymer-coated substrates, demonstrating anisotropic electrical properties over varying strain and energy storage capabilities and showing enormous potential for 3D printable devices.