2018/08/14 by Laura Grebenstein, Jens Kirchner, Grebenstein, Laura +20
Biochemistry, Genetics and Molecular Biology · Engineering · Neuroscience · #Advanced biosensing and bioanalysis techniques #Emerging Technologies (cs.ET) #FOS: Computer and information sciences #Molecular Communication and Nanonetworks #Photoreceptor and optogenetics research
paper · pdf · doi:10.48550/arxiv.1808.05145
openalex publication_date 2018/08/14 · openalex created_date 2022/08/04 · openalex updated_date 2026/07/28
Although many exciting applications of molecular communication (MC) systems\nare envisioned to be at microscale, the MC testbeds reported so far are mostly\nat macroscale. To link the macroworld to the microworld, we propose and\ndemonstrate a biological signal conversion interface that can also be seen as a\nmicroscale modulator. In particular, the proposed interface transduces an\noptical signal, which is controlled using an LED, into a chemical signal by\nchanging the pH of the environment. The modulator is realized using E. coli\nbacteria as microscale entity expressing the light-driven proton pump\ngloeorhodopsin from Gloeobacter violaceus. Upon inducing external light\nstimuli, these bacteria locally change their surrounding pH level by exporting\nprotons into the environment. To verify the effectiveness of the proposed\noptical-to-chemical signal converter, we analyze the pH signal measured by a pH\nsensor, which serves as receiver. We develop an analytical parametric model for\nthe induced chemical signal as a function of the applied optical signal. Using\nthis model, we derive a training-based channel estimator which estimates the\nparameters of the proposed model to fit the measurement data. We further derive\nthe optimal maximum likelihood detector and a suboptimal low-complexity\ndetector to recover the transmitted data from the measured received signal. It\nis shown that the proposed parametric model is in good agreement with the\nmeasurement data. Moreover, for an example scenario, we show that the proposed\nsetup is able to successfully convert an optical signal representing a sequence\nof binary symbols into a chemical signal with a bit rate of 1 bit/minute and\nrecover the transmitted data from the chemical signal using the proposed\nestimation and detection~schemes. The proposed modulator may form the basis for\nfuture MC testbeds and applications at microscale.\n