Internet of Paint (IoP): Channel Modeling and Capacity Analysis for Terahertz Electromagnetic Nanonetworks Embedded in Paint

TL;DR

This work addresses nano-scale THz communication within paint by formulating a five-path channel model across air, paint, and plaster and deriving closed-form path-loss expressions for direct, reflected, and lateral waves. It then develops a multi-band channel capacity model by partitioning the $0.1-10$ THz band into sub-bands and computing aggregate capacity under paint absorption and molecular noise. Numerical results show that paint induces substantial attenuation and reduces capacity by about two orders of magnitude compared to air, while lateral waves near interfaces can offer favorable paths at short burial depths. The findings provide design guidance for dense IoP deployments, interface-aware beam steering, and wall-integrated sensing or RIS applications in indoor environments.

Abstract

This work opens a new chapter in the 100,000 year-old concept of paint, by leveraging innovations in nano-technology in the sub-THz frequency range. More specifically, the groundbreaking concept of Internet of Paint (IoP) is introduced along with a comprehensive channel model and a capacity analysis for nano-scale radios embedded in paint and communicating through paint. Nano-network devices, integrated within a paint medium, communicate via a multipath strategy, encompassing direct waves, reflections from interfaces, and lateral wave propagation. The evaluation incorporates three distinct paint types to assess path losses, received powers, and channel capacity. Analysis of path loss indicates a slight non-linear increase with both frequency and Line of Sight (LoS) distance between transceivers. Notably, paints with high refractive indexes result in the highest path loss. Moreover, burying transceivers at similar depths near the Air-Paint interface showcases promising performance of lateral waves with increasing LoS distance. Increasing paint layer depth leads to amplified attenuation, while total received power exhibits promising results when in close proximity to the Air-Paint interface but steeply declines with burial depth. Additionally, a substantial reduction in channel capacity is observed with LoS distance and burial depth, so transceivers need to be close together and in proximity of the A-P interface to communicate effectively. Comparing paint and air mediums, IoP demonstrates approximately two orders of magnitude reduction in channel capacity compared to air-based communication channels. This paper provides valuable insights into the potential of IoP communication within paint mediums and offers a foundation for further advancements in this emerging field.

Figures (17)

• Figure 1: Internet of Paint (IoP) where nano-devices are embedded into the paint mixture and applied onto a wall, enabling nano-network communication at short range using THz frequencies.
• Figure 2: Illustration of nano-devices embedded in paint resulting in direct path, reflected paths, as well as lateral waves that can propagate along the air-path as well as paint-plaster interface.
• Figure 3: Geometry wave reflected from the Air-Paint interface, indicating specific angles of reflection will result in perfect wave alignment to the receiver.
• Figure 4: Geometry for the waves reflected from the Paint-Plaster interface, resulting in specific waves that reflect and align to the receiver as well as lateral waves that travel along the paint-plaster interface.
• Figure 5: Geometry for refracted waves that results in Lateral waves propagating along the Air-Paint interface, where energy leakage back into the paint resulting in a wave refraction to the receiver.