Increasing the Communication Distance between Nano-Biosensing Implants and Wearable Devices

Significant progress in the fields of electronics, photonics and wireless communications have enabled the development of compact wearable devices, with applications in diverse domains such as fitness, wellness and healthcare. In parallel, nanotechnology is facilitating the development of nano-biosensors, i.e., miniaturized sensors that can be implanted subcutaneously and measure various types of biological events at the nanoscale with unprecedented accuracy. The majority of nano-biosensing systems consist of an external optical excitation and measurement device that can induce and measure the response of implanted optical resonant nano-biosensors. However, the high path-loss of the human body at optical frequencies and the weak response of nano-biosensors would compromise the communication between the body-mounted optical excitation/measurement system and the intra-body implant. In this paper, mechanisms are proposed to overcome the high intra-body path-loss and enable wireless communications with deeper implants. More specifically, the combination of analog beam-forming with optical nano-antenna arrays together with light-guiding hydrogel implants is studied to overcome the spreading loss and to increase the intra-body wireless communication distance. The proposed scheme is analytically modeled and validated through simulations to benchmark its performances against the traditional methods.