"Gee I wonder why everyone I talk To Is Always Complaining That they are burnt out and feel tiered all the time?" - Well actually I don't wonder why because I know exactly why because I actually Read!

Joint Energy Harvesting and Communication Analysis for Perpetual Wireless Nanosensor Networks in the Terahertz Band
https://ieeexplore.ieee.org/document/6144047
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Wearable Energy Harvesting: From body to battery
https://ieeexplore.ieee.org/document/7930169
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Wirelessly networked systems of intra-body sensors and actuators could enable revolutionary applications at the intersection between biomedical science, networking, and control with a strong potential to advance medical treatment of major diseases of our times. Yet, most research to date has focused on communications among devices interconnected through traditional electromagnetic radio-frequency (RF) carrier waves. The main obstacle to enabling this vision of networked implantable devices is posed by the physical nature of propagation in the human body; composed primarily (65%) of water, through which RF electromagnetic waves notoriously hardly propagate, even at relatively low frequencies.  
We take a different perspective and propose to investigate and study the use of ultrasonic waves to wirelessly internetwork intra-body devices.
https://ece.northeastern.edu/wineslab/ultrasonic_IBAN.php
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Nano-Enriched Self-Powered Wireless Body Area Network for Sustainable Health Monitoring Services
https://www.mdpi.com/1424-8220/23/5/2633
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Energy Harvesting in Electromagnetic Nanonetworks
https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://cis.temple.edu/~shahram/EHMagV17.pdf&ved=2ahUKEwiO35ao2qSIAxU1mokEHefQPOAQFnoECA8QAQ&usg=AOvVaw0twM-nLeFO84nXF31A4KiE
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An Energy Balance Clustering Routing Protocol for Intra-Body Wireless Nanosensor Networks
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6891516/
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Toward Location-aware In-body Terahertz Nanonetworks with Energy Harvesting
https://www.researchgate.net/publication/363053978_Toward_Location-aware_In-body_Terahertz_Nanonetworks_with_Energy_Harvesting
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On the design of an energy-harvesting protocol stack for Body Area Nano-NETworks
https://www.researchgate.net/publication/269777631_On_the_design_of_an_energy-harvesting_protocol_stack_for_Body_Area_Nano-NETworks
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Electromagnetic Nanonetworks Beyond 6G: From Wearable and Implantable Networks to On-chip and Quantum Communication
https://arxiv.org/html/2405.07812v1