Printed Type Of Antenna Research And Wireless Sensor Member

Printed electronics is electronics based on the principle of printing which using avariety of printing technology——which includes screen printing, flexible printing,gravure printing, offset printing and inkjet printing——to produce electronic devicesand systems. With the development of Internet of Things, antennas and sensors aremore and more attractive to people. The low-cost, high-performance electronicdevices which are made by flexible printing technology are expected to be applied inthe Internet of Things. This paper studied flexible gravure printing technology, theperformance of printed antennas and wireless stress sensor.The first part of this paper studied the technology of gravure printing and theprinted antennas. First, carbon ink, nano silver ink and transparent conductive inkwere printed on coated papers, polyethylene terephthalate (PET) and polyimide (PI).We studied the characteristics of different kind of conductive ink by making acontrast of the ink transfer effects, graphics resolution and resistance of the printedfilm to get the best technical parameters of printing different conductive ink toprepare printed device. Secondly, we studied the production process of the planarcliché in gravure printing in order to develop a suitable planar cliché—parameters ofthe hole is120/3/110(Angle of the needle, Angle of the cells, line density)—for theexperiment. Finally, according to the basic principles of half-wave dipole and thecharacteristics of the folded dipole antenna, a series of antennas whose frequencyrange from0.5GHz to3GHz were designed and simulated by HFSS microwavesimulation software. Flexible printing technology was applied to print these antennason PI substrate with nano silver ink. Agilent5061B was used to test these antennas.We compared the test results with the analog values and the design values.Therefore, the obtained fixed-frequency printed dipole antennas shows goodperformance, which lay foundation for the printed wireless smart sensor research.The second part of the paper printed a wireless pressure sensor with flexiblegravure printing technology, and studied the performance of its stress sensing. Thestress sensor was printed by graphene oxide (GO) ink. After the annealing treatment, the graphene oxide was reduced to graphene. When external force was loaded, thegraphene could be easily deformed because of its special properties, which causedthe changes of electrical properties of the sensor. According to the principle ofelectromagnetic induction Ferrari, the impedance of test antenna (coil antenna) willchange with the changes of electrical properties of sensor, which will be captured byan impedance analyze to achieve the wireless stress sensing function of the sensor. Awired stress test and a wireless stress test were done to the sensor. The impedanceand capacitance of the sensor will change with the load pressure in thecorresponding frequency range in the wired stress test, which is the premise for awireless test, indicating the graphene film has a certain sensitivity to stress. Wirelessstress test showed that as the loaded pressure increases, the impedance of the testantenna increased in the range of27MHz～36MHz, and the resonance frequencyreduced slightly. When the loaded pressure was100N, the sensitivity of the sensorwas48%. We have successfully printed a wireless pressure sensor with goodperformance based on good conductive properties of graphene and it is sensitive topressure, which has reference for the application of printed wireless smart sensor inInternet of Things.The antennas based on flexible gravure printing technology have goodperformance, the printed wireless strain sensor has high sensitivity which can betested by wireless monitoring，provide an experimental basis for printed wirelesssmart sensor and its application in the Internet of Things.