MXene is typically exfoliated by selective etching the A layer of MAX phase. [1] One example of MXene, Ti 3 C 2 F x , satisfies the stoichiometric ratio of n + 1/n, in which M, X, and T stand for transition metals, carbon or nitrogen, terminal groups at surfaces, respectively. The MXene has exhibited extraordinary electrical, [2][3][4] optical, [5] mechanical, [6][7][8] and electrochemical properties [9] since its first discovery, [10] which has become an emerging material for sensing, [11,12] communication, [13,14] energy, [15,16] environmental, [17] and healthcare applications. [18][19][20] There are many reviews existing for electrochemical energy storage, including supercapacitors, lithium ion batteries, [21][22][23] sodium ion batteries, zinc ion batteries, [24][25][26] lithium-sulfur batteries, and energy conversions, [27][28][29] includingThe Internet of Things era has promoted enormous research on sensors, communications, data fusion, and actuators. Among them, sensors are a prerequisite for acquiring the environmental information for delivering to an artificial data center to make decisions. The MXene-based sensors have aroused tremendous interest because of their extraordinary performances. In this review, the electrical, electronic, and optical properties of MXenes are first introduced. Next, the MXene-based sensors are discussed according to the sensing mechanisms such as electronic, electrochemical, and optical methods. Initially, biosensors are introduced based on chemiresistors and field-effect transistors. Besides, the wearable pressure sensor is demonstrated with piezoresistive devices. Third, the electrochemical methods include amperometry and electrochemiluminescence as examples. In addition, the optical approaches refer to surface plasmonic resonance and fluorescence resonance energy transfer. Moreover, the prospects are delivered of multimodal data fusion toward complicated human-like senses. Eventually, future opportunities for MXene research are conveyed in the new material discovery, structure design, and proof-of-concept devices.

Human beings perceive the world through the senses of sight, hearing, smell, taste, touch, space, and balance. The first five senses are prerequisites for people to live. The sensing organs upload information to the nervous systems, including the brain, for interpreting the surrounding environment. Then, the brain sends commands to muscles reflexively to react to stimuli, including light, gas, chemicals, sound, and pressure. MXene, as an emerging two-dimensional material, has been intensively adopted in the applications of various sensors and actuators. In this review, we update the sensors to mimic five primary senses and actuators for stimulating muscles, which employ MXene-based film, membrane, and composite with other functional materials. First, a brief introduction is delivered for the structure, properties, and synthesis methods of MXenes. Then, we feed the readers the recent reports on the MXene-derived image sensors as artificial retinas, gas sensors, chemical biosensors, acoustic devices, and tactile sensors for electronic skin. Besides, the actuators of MXene-based composite are introduced. Eventually, future opportunities are given to MXene research based on the requirements of artificial intelligence and humanoid robot, which may induce prospects in accompanying healthcare and biomedical engineering applications.