The design, fabrication, and applications of flexible biosensing devices

Abstract

Flexible biosensors form part of a rapidly growing research field that take advantage of a multidisciplinary approach involving materials, fabrication and design strategies to be able to function at biological interfaces that may be soft, intrinsically curvy, irregular, or elastic. Numerous exciting advancements are being proposed and developed each year towards applications in healthcare, fundamental biomedical research, food safety and environmental monitoring. In order to place these developments in perspective, this review is intended to present an overview on field of flexible biosensor development. We endeavor to show how this subset of the broader field of flexible and wearable devices presents unique characteristics inherent in their design. Initially, a discussion on the structure of flexible biosensors is presented to address the critical issues specific to their design. We then summarize the different materials as substrates that can resist mechanical deformation while retaining their function of the bioreceptors and active elements. Several examples of flexible biosensors are presented based on the different environments in which they may be deployed or on the basis of targeted biological analytes. Challenges and future perspectives pertinent to the current and future stages of development are presented. Through these summaries and discussion, this review is expected to provide insights towards a systematic and fundamental understanding for the fabrication and utilization of flexible biosensors, as well as inspire and improve designs for smart and effective devices in the future.

Electrochemical biosensors for pathogen detection

“…Polymer electrode development has been, in part, driven by the need for flexible biosensors. For example, free-standing film electrodes and polymer electrodes on flexible substrates, such as paper, are now being examined for biosensing applications (Xu et al 2019). Given conjugated polymers and polymer composites are compatible with 3D printing processes (Kong et al 2014), polymer electrodes are also emerging as attractive candidates for wearable conformal (i.e., form-fitting) biosensors.…”

Use of Silk Proteins to Form Organic, Flexible, Degradable Biosensors for Metabolite Monitoring

“…In comparison to their rigid counterparts, mechanically flexible sensors are designed to function at non-planar, soft, and even non-stationary bio-interfaces. They can be useful for the accurate detection and quantification of specific biomarkers in clinical diagnosis toward evaluating biological and pathological activities, or response to therapeutic interventions (Xu et al, 2018). Biosensors and bioelectronics characterized by the ability to fully or partially dissolve, disintegrate, or physically or chemically decompose in a controlled fashion in a working environment, can further enhance the applications of flexible devices.…”

“…Devices with properties of biocompatibility, flexibility, and degradability can function as on-body (e.g., wearables) or in vivo (e.g., implantables) monitoring systems for human health, soft robotics, or human-machine interfaces (Wang et al, 2017a(Wang et al, ,b, 2018Feiner and Dvir, 2018;Xu et al, 2018). The use of mechanically compliant substrates allows function in contact with delicate biological interfaces and physical deformation.…”

Nanomaterial‐Modified Conducting Paper: Fabrication, Properties, and Emerging Biomedical Applications

“…Flexible devices are an interesting alternative to the bulky health‐monitoring devices due to their inexpensiveness, excellent flexibility, and lower manufacturing cost. In recent years, many review articles have discussed the characteristics of the flexible devices such as functional textiles, wearable devices, electronic skins, flexible bio‐devices and optoelectronics . In the field of biosensors, many handy and wearable non‐flexible biosensors have been reported, that are used for the measurement of biophysical parameters (heart rate, blood pressure, temperature, pH), and air quality .…”