3D-Printing of Freestanding Pure MXene Microarchitectures.

Since their discovery, titanium-based MXenes (TiCT) have attracted significant attention. Several studies have presented versatile, cost-effective, and scalable approaches for fabricating TiCT-based functional components. However, most previous studies only allowed the realization of 2D patterns or required diverse additives to produce 3D architectures. Herein, a 3D-Printing approach for producing 3D microarchitectures composed entirely of TiCT. TiCT additive-free aqueous ink consists of 0.1 wt.% TiCT nanosheets is proposed. The diameter (d) of the printed TiCT 3D microarchitectures can be determined by controlling the meniscus channel size, which is influenced by the diameter (d) of the micropipette opening and pipette-pulling rate (v). Through optimized control of the pipette, a minimum d of 1.3 µm is obtained, and complex shapes such as zigzag, helix, bridge, and pyramid shapes can be implemented. To demonstrate the feasibility of realizing functional TiCT 3D components, three electrical components are demonstrated: 3D micro-interconnects and 3D transducers for photodetectors and humidity sensors. It is believed that this facile approach can be used for nano 3D-Printing as well as micro printing of TiCT architectures.