3D‐Printing of Freestanding Pure MXene Microarchitectures

Since their discovery, titanium‐based MXenes (Ti3C2Tx) have attracted significant attention. Several studies have presented versatile, cost‐effective, and scalable approaches for fabricating Ti3C2Tx‐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 Ti3C2Tx. Ti3C2Tx additive‐free aqueous ink consists of 0.1 wt.% Ti3C2Tx nanosheets is proposed. The diameter (ds) of the printed Ti3C2Tx 3D microarchitectures can be determined by controlling the meniscus channel size, which is influenced by the diameter (dp) of the micropipette opening and pipette‐pulling rate (v). Through optimized control of the pipette, a minimum ds 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 Ti3C2Tx 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 Ti3C2Tx architectures.