Biodegradable, flexible silicon nanomembrane-based NOx gas sensor system with record-high performance for transient environmental monitors and medical implants

Gwan-Jin Ko,Won Bae Han,Suk-Won Hwang,Jia Zhu,Seung Min Yang,Huanyu Cheng,Jinmook Chung,Jeong-Ki Kim,Dong-Hwee Kim,Chong-Yun Kang,Soo Deok Han

doi:10.1038/s41427-020-00253-0

Abstract

A novel transient electronics technology that is capable of completely dissolving or decomposing in certain conditions after a period of operation offers unprecedented opportunities for medical implants, environmental sensors, and other applications. Here, we describe a biodegradable, flexible silicon-based electronic system that detects NO species with a record-breaking sensitivity of 136 Rs (5 ppm, NO2) and 100-fold selectivity for NO species over other substances with a fast response (~30 s) and recovery (~60 s). The exceptional features primarily depend on not only materials, dimensions, and design layouts but also temperatures and electrical operations. Large-scale sensor arrays in a mechanically pliable configuration exhibit negligible deterioration in performance under various modes of applied loads, consistent with mechanics modeling. In vitro evaluations demonstrate the capability and stability of integrated NOx devices in severe wet environments for biomedical applications.

Highlights

Electronic materials and devices that are biologically benign or mechanically elastic have been utilized in versatile applications, including electronic skin (E-skin) and biomedicine, for the diagnosis and treatment of diseases due to their advantages of nontoxicity, bioresorption, and mechanical properties similar to those of human skin and organs
The results focus on detailed studies of electrical responses of silicon nanomembrane (Si NM) under various conditions, and of the mechanical properties of the electronic system with theoretical considerations
The electronic system consists of patterned single-crystal silicon nanomembranes (SC-Si NMs, thickness ~100 nm) doped with phosphorous using spinon dopant (SOD, Filmtronics) for reactive materials, magnesium (Mg, thickness ~300 nm) as electrodes, silicon dioxide (SiO2, thickness ~100 nm) as interlayer dielectric, and an elastomeric polymer (PDMS, thickness ~20 μm) as a semipermeable membrane to maintain a stable gas sensing performance in humid and wet conditions

Summary

Introduction

Electronic materials and devices that are biologically benign or mechanically elastic have been utilized in versatile applications, including electronic skin (E-skin) and biomedicine, for the diagnosis and treatment of diseases due to their advantages of nontoxicity, bioresorption, and mechanical properties similar to those of human skin and organs. The technological advances in the corresponding areas delivered innovative output products, Ko et al NPG Asia Materials (2020) 12:71 selectivity, high power consumption, and nonbiodegradability, still need to be considered for wearable and implantable electronic systems. We report a flexible and bioresorbable single-crystal silicon nanomembrane (SC-Si NM)-based NOx sensing system operating at room temperature with exceptional sensitivity and selectivity. In vitro assessments that incorporate semipermeable membranes provide information on their potential applicability in disposable environmental monitors and bioresorbable medical implants

Methods

Results

Conclusion