Wearable Devices Using Nanoparticle Chains as Universal Building Blocks with Simple Filtration‐Based Fabrication and Quantum Sensing

Abstract Self‐assembled micrometer long gold nanoparticle chains are used as building block to fabricate a range of flexible devices to monitor human physiological signals by an easy filtration method. The chains serve as the base material for all the devices and their interconnects and contact pads as well. The micrometer long chains are an array of nanoparticles with gaps of 1–2 nm between adjacent particles. The gaps serve as quantum tunneling barrier and their modulation is basis of signal sensing in these devices. Deposited on a flexible membrane, the chains monitor temperature, artery pulsation, and electrocardiograms (ECG) signals with ease. This simple method provides an avenue to fabricate low cost integrated wearable devices based on quantum phenomena.