A Small-scale Modulator of Electric-to-biological Signal Conversion for Synthetic Molecular Communications

Synthetic Molecular communications (SMC), as one of the most promising communication paradigms for internet of nano-things (IoNT), is expected to advance many revolutionary areas such as precision drug delivery and biological engineering. Many of the envisioned applications of SMC are in microscale. However, the state-of-the-art SMC testbeds reported in the literature are mostly in macroscale. The lack of microscale communication sub-systems to enable connectivity between individual nanomachines for basic coordination in IoNT is its key technology hindrance. To solve this issue, we propose a microscale SMC modulator which is a key component of microscale SMC system. The proposed microscale SMC modulator is a signal conversion interface to link the macroworld to microworld. It translates an electric signal into biological DNA signal by electrochemical and electrodissolution technique. The modulator is realized by a layer-by-layer assembly technique to immobilize DNA on the surface of gold thin film. And it triggers the selective release of DNA upon the exclusive control of external electric potential signal. The amount of released DNA depends on the amplitude of applied electric stimuli. The DNA release process can be switched off by removing the external electric stimuli and reactivated by reapplying the stimuli. To examine the effectiveness of the proposed modulator, the released DNA concentration is measured by using Nanodrop which is capable to quantify DNA, RNA, and protein samples. And a detection scheme is proposed for signal detection based on the measured data. Experiments show that the proposed setup is able to successfully convert an electric signal representing a sequence of binary symbols into a DNA biological signal with a bit rate of 1 bit/min. This work may help SMC and IoNT to advance from theoretical research towards practical applications.