Biomolecule‐Interactive Flexible Light Emitting Capacitor Display

Abstract Ultrathin, lightweight, flexible, and conformable interactive displays that transduce external stimuli into human‐readable signals are essential for emerging applications, such as wearable electronics, human–machine interfaces, and soft robots. Herein, a biomolecule‐interactive flexible light emitting capacitor (LEC) display (BIO‐LEC) capable of dynamic and quantitative visualization of biomolecules through naked‐eye detectable electroluminescence (EL) emission is reported. BIO‐LEC comprises a coplanar LEC light source at the bottom, and a designed microfluidic chip as sampling compartment at the top. The quantitative measurement feature of BIO‐LEC is achieved by introducing the top liquid electrode, which possesses a unique long dielectric realization time, in the microfluidic chip. BIO‐LEC is novel for the following reasons, 1) simple stimuli response principle based on correlating EL intensity to dielectric properties of the top liquid electrode; 2) simple test conditions whereby no labeling is required in the analyte solution to optically detect biomolecules; 3) effective sampling method through the design of an integrated microfluidic chip for hosting the top liquid electrode, ensuring good reproducibility and preventing contamination; 4) sensitive detection limit for heparin concentrations at clinically relevant levels, and 5) high compliance with industrial manufacturing standards.