Biomolecular Networking of Nano-Implants Enable Wireless Communication in the Bloodstream

Biological computing machines such as micro- and nano-implants transform medicine by allowing experts to collect vital information inside the human body. The challenge, however, lies in successfully networking these implants for seamless communication.

Challenges in IoBNT

Between 2008 and 2009, the Internet of Things (IoT) was conceived when the number of connected machines surpassed the number of humans on Earth. Now, at the interface of computer science and biology, the Internet of Bio-Nano Things (IoBNT) promises to revolutionize health care and medicine.

The IoBNT refers to biosensors that can perform various functions such as data collection and processing, running medical tests inside the body, and using bacteria to design biological nano-machines to detect pathogens. It may also involve robots that swim through the bloodstream to perform targeted drug delivery and treatment.

With advances in nanotechnology, synthetic biology, and bio-engineering, nano-biosensors are expected to revolutionize medicine since they can reach places and do things that larger implants and current devices cannot.

No matter how exciting this research field is, communicating a nano-robot inside a person's body is still a fundamental challenge. Traditional techniques work well for large implants but cannot be scaled down to micro- and nano-dimensions. Aside from this, wireless signals do not penetrate through body fluids.

Networking Nano-implants

This is where biomolecular communication comes into play, mimicking the existing communication mechanisms in biology. This process does not utilize electromagnetic waves but instead uses biological molecules as carriers and information. In its simplest form, biomolecular communication encodes "1" and "0" bits by releasing or not releasing molecular particles into the bloodstream.

According to Ecole Polytechnique Federale de Lausanne (EPFL) assistant professor Haitham Al Hassanieh, biomolecular communication has emerged as the most suitable paradigm for networking nano-implants. Through this process, experts can send data by encoding it into molecules that go through the bloodstream. Then, they can communicate with them and guide them on where to go and when to release their treatments.

In a recent study, Al Hassanieh and his team outlined their Molecular Multiple Access (MoMA) protocol, which enables a molecular network with multiple transmitters. Their paper, "Towards Practical and Scalable Molecular Networks," was presented at ACM SIGCOMM 2023.

Existing studies are very theoretical and do not work because the theories have not considered biology. Most theories also assume that the channel sent to the molecules is stable and does not change. In reality, the changes occur very fast.

The research team introduced encoding/ decoding schemes, channel estimation, and packet detection, which leverage the unique properties of molecular networks to address existing challenges. They used a synthetic experimental testbed in evaluating the protocol, demonstrating its ability to scale up to four transmitters while outperforming state-of-the-art technology.

The scientists acknowledge that their current synthetic testbed may not capture all the challenges in designing protocols for molecular networks. They also need to achieve practical and deployable molecular networks by in-vivo testing of micro-implants and micro-fluids in wet labs. Still, the team believes that their testbed's underlying diffusion and fluid dynamics models are fundamental to molecular communication.