Preparation Of Pure Aqueous Ti₃C₂ Ink And Application In Printing And Manufacturing Flexible Antenna

The vigorous development of emerging technologies,including wearable devices,5G technology,communication devices,intelligent fabrics,embedded electronics,and the Internet of Things,has made integrated wireless communication devices ubiquitous.The demand for lightweight,thin and flexible antenna components for miniaturized and wearable devices has been increased rapidly.In the process of antenna information transmission,due to the requirements of microwave communication performance,traditional antennas are composed of highly conductive metals.However,the relatively large quality,poor flexibility and complex manufacturing process of metal antenna limit the development of compact and flexible communication equipment.In order to meet the rapid development of application requirements,the targeted design and preparation of flexible antenna devices with light weight and conformability is the driving force for the sustainable development of the research in the field of information transmission,and is also the key to the research in this field.Due to its good hydrophilicity and easily adjustable rheological range,Ti₃C₂ink can form stable dispersions in a variety of solvents.As a common material for high-quality devices made by printing and patterning,Ti₃C₂ink is widely used in energy storage,sensors,electromagnetic shielding and other fields.Its high conductivity,light weight,flexibility,easy processing and other characteristics are very consistent with the application requirements of flexible information transmission devices.Therefore,Ti₃C₂materials begin to emerge in the field of microwave communication.However,the research results on Ti₃C₂ antenna are very limited at present.There are some defects such as limited categories,complex structures,and rough production technology,which largely limit its application in the direction of flexible microwave devices.Therefore,simplifying the antenna hierarchy,improving the device preparation accuracy,studying the rheological characteristics of Ti₃C₂ ink,and improving the mechanical stability of the antenna have become many problems that need to be solved urgently on the practical road of Ti₃C₂ flexible communication devices.In this paper,by modifying the flexible medium substrate,the printed Ti₃C₂ ink can form a good force on the substrate surface and maintain excellent stability and information transmission effect.By adjusting and controlling the change of printing parameters,the antenna transmission performance is controlled to achieve the information communication function.The details are as follows:（1）In order to solve the problems of low precision and complex structure of Ti₃C₂ antenna,this paper designed a preparation process combining high-precision printing and molecular glue.By controlling the viscosity of printing ink(60 mg m L^-1),Ti₃C₂ ink is obtained,which has a yield stress of about 50Pa,a viscosity that changes rapidly with the shear rate,and a controllable rheological property of Ti₃C₂ ink,so as to control the fineness in the printing process.In addition,using the rich functional groups（-NH₂,-OH,etc.）contained in the surface of polydopamine（PDA）and its excellent adhesion performance,Ti₃C₂ ink was printed on the commercial F4B dielectric substrate to obtain a monopole antenna with simple longitudinal structure.Thanks to the high conductivity of Ti₃C₂ ink(6000 S cm^-1),the obtained monopole antenna has good communication performance.It can maintain excellent radiation direction（full radiation）at most frequencies in the working range of 1.8–4.0 GHz.At the central working frequency of 2.2–2.4 GHz,it can maintain high radiation efficiency（>70%）and high gain（>2 d Bi）of the antenna.In the process of real-time signal transmission,the communication satellite image remains compact without obvious divergence,and the bit error rate is low,so it can transmit video signals completely and quickly.In addition,based on the excellent adhesion and surface functional groups of PDA,the monopole antenna obtained still maintains good performance after 1000 times of bending,and the curve and gain change of S₁₁ are very stable.We have successfully prepared a Ti₃C₂ antenna with simple structure and excellent transmission performance,making it a big step forward in practicality.（2）In order to realize the high-quality and multi-function application of Ti₃C₂ antenna in portable electronic equipment,we tested the antenna’s long-range stability,temperature and humidity sensitivity,long-distance transmission,and other characteristics.In view of the performance degradation of Ti₃C₂ antenna caused by long-term exposure to air,we first detected the performance change of pure Ti₃C₂ antenna within 30 days as a reference,and prepared Ti₃C₂/DA antenna based on the principle of dopamine（DA）delaying the oxidation of nano sheet as a control.The resistance of Ti₃C₂/DA composite material is too large,and the antenna S₁₁ prepared with it is always greater than-10 d B,that is,the signal cannot be transmitted due to the poor conductivity of the material;In addition,in the functional test of the antenna,it is found that it is more sensitive to humidity when the relative humidity is 50-70%.In the temperature range of 30-75 ^oC,the overall amplitude and resonance point regularly decline with the temperature rise,which proves that the antenna can be used as a temperature sensor while having the function of transmitting information;Finally,simulate various transmission types of the Ti₃C₂ antenna in actual use to detect its transmission quality in different distances,directions,and stable states.The experimental results show that in most environments,the Ti₃C₂ antenna can transmit information normally.The flexible antenna with excellent stability,high performance,multi-function and stable transmission is realized,which broadens the application range of Ti₃C₂ antenna.