"Low-cost Microfluidic Testbed for Molecular Communications with Integrated Hydrodynamic Gating and Screen-printed Sensors"

"Molecular Communications (MC), transferring information via chemical signals, holds promise for transformative healthcare applications within the Internet of Bio-Nano Things (IoBNT) framework. Despite promising advances toward practical MC systems, progress has been constrained by experimental testbeds that are costly, difficult to customize, and require labor-intensive fabrication. Here, we address these challenges by introducing a low-cost ($\\sim$\\$1 per unit), rapidly fabricated ($<$1 hour), and highly customizable microfluidic testbed \\textcolor{blue}{that integrates a cross-shaped, hydrodynamic gating-based microfluidic transmitter, and a screen-printed potentiometric sensor-based receiver.}. This platform enables precise spatiotemporal control over chemical signals and supports reconfigurable channel architectures along with on-demand sensor functionalization. As a proof of concept, we demonstrate a pH-based MC system combining a polyaniline (PANI)-functionalized screen printed sensor for real-time pH signal detection with a programmable hydrodynamic gating architecture, patterned in a double-sided adhesive tape, as the transmitter. By dynamically mixing phosphate-buffered saline (PBS) with an acidic solution (pH 3), the testbed reliably generates pH-encoded pulses. Experimental results confirm robust control over pulse amplitude and pulse width, enabling the simulation of end-to-end MC scenarios with 4-ary concentration shift keying (CSK) modulation. By combining affordability and rapid prototyping without compromising customizability, this platform is poised to accelerate the translation of MC concepts into practical IoBNT applications."

分子通信（Molecular Communications, MC）即通过化学信号传递信息，在生物纳米物联网（Internet of Bio-Nano Things, IoBNT）框架下展现出变革性医疗应用的巨大潜力。尽管实用型分子通信系统的研发已取得可喜进展，但相关进展却受限于现有实验测试平台：其成本高昂、定制难度大且制备过程需耗费大量人力。为此，本文提出一款低成本（约每台1美元）、快速制备（耗时不足1小时）且可高度定制的微流控测试平台，该平台集成了十字形流体门控微流控发射器与基于丝网印刷电位式传感器的接收器。该平台可对化学信号实现精准的时空控制，支持可重构信道架构与按需传感器功能化。作为概念验证，我们演示了一套基于pH值的分子通信系统：其发射器为采用双面胶带制备的可编程流体门控架构，接收器则为经聚苯胺（Polyaniline, PANI）功能化的丝网印刷传感器，用于实时检测pH信号。通过将磷酸盐缓冲生理盐水（Phosphate-Buffered Saline, PBS）与酸性溶液（pH 3）动态混合，该测试平台可稳定生成pH编码脉冲。实验结果证实，其可对脉冲幅度与脉冲宽度实现精准控制，能够模拟采用4进制浓度移位键控（Concentration Shift Keying, CSK）调制的端到端分子通信场景。本平台兼具低成本、快速原型开发能力与高度定制化优势，有望加速分子通信理念向实用型生物纳米物联网应用的转化。