Abstract—Recent advances in nano-materials and nanotechnology have paved the way for building integrated devices with a nanometric size, named nano-nodes. These nano- nodes are composed of nano-processor, nano-memory, nano- batteries, nano-transceiver, nano-antenna and nano-sensors, which operate at nano-scale level. They are able to perform simple tasks, such as sensing, computing and actuation. The interconnection between microdevices and nanonodes/nanosensors has enabled the development of a new network standard, called Wireless Nano-Sensors Network (WNSN). This paper provides an in-depth review of WNSN, its architectures, application areas, and challenges, which need to be addressed, while identifying opportunities for their implementation in various application domains.
Index Terms—Nanotechnology, nanosensors, wireless nan- sensors network, protocols and applications
I. INTRODUCTION Recent advances in nanomaterials and nanotechnology have enabled the development of tiny nanoscale devices, named nanonodes or nanomachines. Composed of a nano- battery, a memory, an antenna and an actuation unit, the nanomachines are fully autonomous nano-nodes able to execute simple operations while communicating at short distances . Wireless nano-nodes, which are able to detect and interact with their environment, will bring radical changes to everyday life applications . However, due to their tiny size, energy and physical (e.g. computation, storage) capacities are extremely limited. As a result, interesting applications, using wireless nano- sensors communications network (WNSN), may require thousands of cooperating nanonodes . For instance, nanoscale devices, which operate at the nanoscale level, could provide very important technological solutions in various fields, including biology, military, agriculture, smart cities, environmental and food safety -. For example, nanosensors could detect chemical compounds at atomic level or the existence of toxic substances in the air/water .
WNSN networks will increase the efficiency of nano- devices by allowing them to perform simple sensing and computation operations. Data sensed at nano-scale level could be submitted and shared with other nodes, via hop- by-hop routing and dissemination protocols (e.g., flooding). Alike traditional networks, nano-routers play an important role, by routing and communicating data from source nodes to the nano-interface device, which acts as a bridge between the nano world and the micro world. The interconnection between these nanonodes can be achieved by one of the following communication mechanisms: electromagnetic, acoustic, nanomechanical and molecular communication  . In this paper, we focus on the nano-electromagnetic communication. It is based on the transmission and reception of radio frequency electromagnetic waves in the Terahertz band using nanomaterial-based antennas, in particular graphene-based antennas, and nano transceivers .
The remainder of this paper is structured as follows. We first present, in Section 2, a general overview of the architecture of nanodevices as basic elements of WNSNs, then we describe a typical architecture model for an EM- based WNSN in Section 3. Opportunities, which can be realized for WNSN applications, are highlighted in Section 4. In Section 5, we describe the main challenges of implementing WNSN applications, in particular those related to the deployment, data analysis, routing technology and coexistence with other categories of networks. Conclusions and perspectives are given in Section 6.