Molecular communication considers the use of molecules as carriers of information between nodes, and it is an inter-disciplinary domain at the intersection of communications theory, physical chemistry, and biology. Progress in this field can improve our understanding of biological processes while also enabling the design and deployment of novel communication networks in biological and fluid environments. For example, molecular communication theory could eventually be applied to understand and treat neurological disorders, prevent the growth of cancerous tumors, and mitigate the impact of other illnesses that arise due to ineffective or unintended molecular signaling. Novel systems based on molecular communication could advance applications such as targeted drug delivery, sensitive environmental monitoring, and lab-on-a-chip systems.
The field of molecular communication has experienced significant growth in the past several years, as exemplified by the following recent advancements:
- Founding of the IEEE (Institute of Electrical and Electronics Engineers) journal IEEE Transactions on Molecular, Biological, and Multi-Scale Communications in 2015.
- Founding of the Elsevier journal Nano Communication Networks in 2010.
- Founding of the ACM (Association for Computing Machinery) International Conference on Nanoscale Computing and Communication (NanoCom) in 2014.
- Tracks on Nanoscale, Molecular, and Quantum Networking in the Selected Areas in Communications Symposium at the flagship conferences of the IEEE Communications Society (ComSoc) since 2014.
- The standard IEEE 1906.1 — Recommended Practice for Nanoscale and Molecular Communication Framework was approved in 2016.
Our long-term objective is to use communications and signal processing tools to improve the understanding of biochemical processes and how to interact with them at a microscopic level. Our on-going topics are all advancements towards this objective. Ultimately, we hope that this research can be coupled with advancements in nanotechnology to aid in the advancement of medical treatments and other applications that rely on the release and detection of molecules. Analytical models and results should also be supported by experimental data wherever possible.
We have motivated the need for a simulation framework of reaction-diffusion systems that is easily scalable in physical dimensions, chemical complexity, and computational requirements. Such a tool would be very useful to the molecular communication research community while also relevant for the broader physical chemistry community.
Our goal is to accurately capture the receiver statistics while improving computational efficiency in other regions of the simulation environment. Doing this would facilitate the large number of iterations required to generate and verify the statistics. To this end, we are developing AcCoRD (Actor-based Communication via Reaction-Diffusion) as an open source project.
Transceiver Behavior in Molecular Communication Systems
The existing literature on the transmitters and receivers (i.e., nodes) in molecular communication systems has generally assumed that they are ideal nodes that operate purely for the transfer of digital information and will always operate as intended in a static and empty environment. These assumptions have been suitable for establishing tractable limits on communications performance. However, in reality the presence of a molecular communication system might unintentionally disrupt or interfere with the natural environmental state. Furthermore, the transmitters and receivers might have different intended purposes and may not cooperate as desired, especially if one node is a normal biological cell and the other was manufactured synthetically. These realistic factors should be considered to model the practical impact of a molecular communication system. We are considering several problems and solutions from this perspective, with the objective of gaining insight into how the nodes might behave and obtaining meaningful communications performance while maintaining the integrity of the environment. They are as follows:
- Game Theoretic Modeling of Molecular Communication Systems
- Avoiding Environmental Toxicity and Interference
- Security of Molecular Communication Links
- Practical Channel Parameter Estimation
Information Theoretic Modeling of Biochemical Processes
Existing biochemical processes in natural biological systems can be used to transfer large quantities of information. We do not have a complete understanding of how much information is transferred and exactly what this information is. We are considering the following problems that focus on specific biochemical processes and use information theoretic tools to study their potential for communication:
- Measuring Information from Neural Impulses
- Mutual Information of Chemical Reactions
Improving Molecular Communication Channel Models
In practice, there are many phenomena that can influence the trajectory of a diffusing molecule. However, the number of phenomena that have been considered in molecular communication models has been limited thus far. Most literature has considered propagation via pure diffusion only, with some consideration of chemical reaction mechanisms and simple flow modeling. We propose several physical phenomena that merit further study because they could be encountered in a natural setting or could be introduced to improve communication. For each of these phenomena, both analytical models and appropriate simulation methods are needed:
- Impact of Molecule Charge or Polarity
- Molecular Communication in the Presence of Electric Fields
- Improving Realism of Flow Models