[Paper Review] Theoretical Modeling of KHz to THz Simultaneous Energy Harvesting and Magneto-Inductive Communications with Molecular Magnets on Vibrating Graphene

Burhan Gülbahar|arXiv (Cornell University)|Feb 21, 2018

Molecular Junctions and Nanostructures25 references3 citations

TL;DR

This paper proposes a nanoscale transceiver that simultaneously harvests energy and enables magneto-inductive (MI) THz communications using graphene resonators coupled with single molecular magnets (SMMs), specifically TbPc₂. By leveraging graphene's high resonance frequencies and the SMM's strong magnetic moment, the design achieves tens of nanowatts of harvested power and efficiency up to $10^4 \, \text{W/m}^3$ in acoustic and ultrasound bands, with numerical validation of millimeter-wave carrier generation for real-time wireless information and power transfer (SWIPT).

ABSTRACT

Magneto-inductive (MI) THz wireless communications is recently shown to provide significant theoretical performances for nanoscale applications with microscale transceivers and microwatt transmission powers. The energy harvesting (EH) based generation of carrier signals for MI transceivers is critical for the autonomous and noninvasive operation. State-of-the-art electromagnetic (EM) vibrational devices have millimeter dimensions while targeting only low frequency EH without any real-time communications purpose. In this article, graphene nanoscale resonators are combined with single molecular magnets (SMMs) to realize a simultaneous EH and MI transceiver by exploiting the unique advantages of graphene such as atomic thickness, ultra-low weight, high strain and the resonance frequencies reaching THz with the high magnetic moment of Terbium(III) bis(phthalocyanine) ($\mbox{TbPc}_2$) SMM. The special low complexity design is improved by novel modulation methods achieving simultaneous wireless information and power transfer (SWIPT). The numerical simulations provide tens of nanowatt powers and efficiencies of $10^4 \, W/m^3$ in acoustic and ultrasound frequencies comparable with state-of-the-art vibrational EH devices while millimeter wave carrier generation is numerically simulated. The proposed design presents a practical framework for nanoscale communications including cellular tracking.

Motivation & Objective

• To enable autonomous, noninvasive nanoscale wireless communication and energy harvesting using molecular-scale components.
• To overcome the limitations of existing vibrational energy harvesters that operate only at low frequencies and lack real-time communication capability.
• To integrate single molecular magnets (SMMs) with graphene nanoresonators to achieve simultaneous wireless information and power transfer (SWIPT) at THz frequencies.
• To develop a low-complexity, high-efficiency design suitable for nanoscale applications such as cellular tracking and implantable devices.

Proposed method

• Utilizes graphene nanoscale resonators with atomic thickness and high strain to achieve resonance frequencies in the THz range.
• Integrates Terbium(III) bis(phthalocyanine) ($\mbox{TbPc}_2$) SMMs due to their high magnetic moment, enabling strong magneto-inductive coupling.
• Employs novel modulation techniques to enable simultaneous wireless information and power transfer (SWIPT) within the same system.
• Numerically models the system's performance in acoustic and ultrasound frequency bands to evaluate energy harvesting efficiency and power output.
• Simulates millimeter-wave carrier generation for magneto-inductive communication using the SMM-graphene hybrid structure.
• Analyzes power harvesting efficiency in terms of $W/m^3$ to benchmark against state-of-the-art vibrational energy harvesters.

Experimental results

Research questions

• RQ1 Can a graphene-SMM hybrid structure achieve efficient energy harvesting in the acoustic and ultrasound frequency bands while enabling THz magneto-inductive communication?
• RQ2 What is the maximum energy harvesting efficiency achievable with this nanoscale transceiver design compared to existing vibrational energy harvesters?
• RQ3 How does the integration of $\mbox{TbPc}_2$ SMMs with graphene resonators enable simultaneous wireless information and power transfer (SWIPT) at high frequencies?
• RQ4 To what extent can the system generate usable carrier signals for MI communication at millimeter-wave frequencies through mechanical resonance?
• RQ5 Can this design support practical nanoscale applications such as cellular tracking with autonomous power and communication?

Key findings

• The proposed system achieves tens of nanowatts of harvested power in the acoustic and ultrasound frequency bands.
• Energy harvesting efficiency reaches up to $10^4 \, \text{W/m}^3$, comparable to state-of-the-art vibrational energy harvesters.
• Numerical simulations confirm the feasibility of millimeter-wave carrier generation for magneto-inductive communication using the SMM-graphene hybrid.
• The design enables simultaneous wireless information and power transfer (SWIPT) through novel modulation methods integrated into the low-complexity structure.
• The combination of graphene’s high resonance frequency and the high magnetic moment of $\mbox{TbPc}_2$ SMMs supports nanoscale, autonomous, and noninvasive operation.
• The framework presents a practical solution for nanoscale wireless systems, including potential applications in cellular tracking and implantable biosensors.