Research On Molecular Communication System Model Based On Diffusion Channel

With the development of powerful electronic devices, the size of the chip be-comes smaller and smaller, which makes Moore's Law cannot hold forever. The fabri-cation of the chip will enter the era of Nano Electronics, and small scale devices for communication are needed, such as nanomachine, the size of which ranges from 1nm to 100nm. There are three different approaches for the development of nanomachine, top-down approach, bottom-up approach and bio-hybrid approach. Due to the limita-tion of single nanomachine's abilities, the inter-connection of nanomachines is ex-pected to cooperate and share information, forming the nanonetwork. There are mainly four ways for the communication of nanomachines to form a nanonetwork:nanome-chanical, acoustic, electromagnetic and molecular communication, of which molecular communication is naturally bio-hybrid and energy-efficient. Moreover, molecular communication has a wide range of application in biomedical, environment, industrial, military and future communication field.More and more researchers pay attention to the molecular communication, but the development of the field is still in its infancy, for it is highly inter-disciplinary and dif-ficult to coordinate researchers from different disciplines. Also the laboratory experi-mentation of molecular communication can be laborious, time consuming and expen-sive. Therefore, the field lacks test beds to show and verify the theoretical result. In 2013, York University (Canada) developed the first test bed "Kinboshi" for macroscale molecular communication combined with the University of Warwick and Yonsei Univer-sity. Kinboshi is based on drift diffusion and the transmitter is several meters away from the receiver, however, in nature, the molecular communication is mainly in the forms of short distance and free diffusion (pure diffusion). In this thesis, considering the gravity, a vertical channel model of molecular communication is proposed, which may be used in the transpiration of biological, biological pump of the ocean, etc., and then we set up a test bed to verify the impulse of the channel. We named the test bed "Ares".The main research work of this paper is composed of the following parts:(1) Reviewed the fundamental knowledge of molecular communication. This the- sis reviewed some fundamental knowledge of molecular communication, such as mo-lecular communication model, modulation techniques, channel model and so on, which will be helpful for new researchers to entry into this field.(2) Proposed a vertical channel model based on diffusion. Inspired by the shape of the spring, in the vertical direction, by spraying a certain quantities of information molecules, some of the information molecules will reach a peak distance, which can be applied into target drug delivery to coordinate the distance and quantities of medicine. Therefore, the general channel model of the vertical molecular communication was proposed.(3) Set up a test bed of vertical molecular communication. Compared with the Kinboshi, the test bed did not have fan, and also it is in a closed environment, making a more reliable test bed to imitate the environment of molecular communication in na-ture and remove the noise. The transmitter of the test bed is composed of Arduino mi-crocontroller, LCD Keypad Shield, and the spray. The channel is made of alcohol molecules which transmitter in the air at a short distance. The receiver consists of Ar-duino microcontroller, LCD Keypad Shield, and the MQ-3 alcohol sensor. The LCD Keypad Shield can be used to input the characters intending to send to the receiver. Only some power is need, the test bed can be used independently and easy to carry.(4) Get the proper channel model for the Ares test bed through data fitting. We compared the previous theory of molecular communication based on diffusion with the data from the test bed. Analyzing the data, by using nonlinear least square method, we get a more accurate channel model in certain condition, which will be useful in the fu-ture work of molecular communication.