Review—Recent Progress in the Diversity of Inkjet-Printed Flexible Sensor Structures in Biomedical Engineering Applications

Abstract

In this review, we summarize the latest advances in the development of various flexible sensors structure platforms fabricated by the inkjet printing technique. We first explain in general the type of biosensors which includes tactile sensors published recently that highlighted their features and uses, sensors architecture or platform and advantages of the designed platform. For better understanding of the inkjet printing process, we include the working inkjet printing system and strategy of ink jet printing process for quality and effective design of flexible and wearable applications. Then, we reviewed the types of biosensors and tactile sensor focusing on the flexible and wearable features subsequently highlighting several types of sensors fabricated via the inkjet printing method. The sensors highlighted were based on different types of sensor platforms namely the field effect transistor, standard electrode and special geometrical structure. The focus of insights for the different types of sensors platform were based on the operation, design and processing of inkjet-printed components. Lastly, an outlook on future challenges and research opportunities on inkjet-printed flexible biosensor for research development based on engineering and fundamental science in achieving effectiveness and reliability of inkjet-printed sensors is presented.

Inkjet Printing: A Viable Technology for Biosensor Fabrication

“…The first patented inkjet-printed enzyme-based biosensor was developed in 1988 [48]. Since then, inkjet printing has been extensively used for the high throughput, low-cost, rapid, and simple fabrication of biosensor prototypes, and become a viable technology for the biosensors industry [15,79,145].…”

“…Compared to the optical and mass-based biosensors, electrochemical sensors offer miniaturization, simple fabrication, and customized readout circuits [14]. A detailed description of the transduction systems and types of biosensors can be found in a recent review article [15].…”

“…Compared to the optical and mass-based biosensors, electrochemical sensors offer miniaturization, simple fabrication, and customized readout circuits [14]. A detailed description of the transduction systems and types of biosensors can be found in a recent review article [15]. Biosensors applications: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has undoubtedly been devastating, causing approximately 5.4 million deaths globally as of December 30 th , 2021 according to the World Health Organization (WHO).…”

“…Printed Biosensors: The current advanced printing and deposition methods for biosensor fabrication can be classified into two categories; (i) the direct deposition and patterning of material onto the desired substrate, and (ii) the transfer deposition of pre-patterned material onto the substrate. The former technique is achieved via contact (all mask-based techniques) [49,50] and non-contact printing (maskless printing) [15,50,51] technologies, while the latter is achieved by a transfer print after the patterns are brought about via the conventional lithography [52][53][54][55][56][57] or plasma-modification techniques [58][59][60]. An immense amount of research has been carried out in the pursuit of fabrication techniques that (i) require a minimum number of fabrication steps, (ii) are flexible in the usage of printable inks, and (iii) are compatible with the appropriate application-based substrates [61].…”

An Inkjet Printed Flexible Electrocorticography (ECoG) Microelectrode Array on a Thin Parylene-C Film

“…Inkjet printing can be an alternative fabrication method that can create narrow and thin microelectrode patterns using various kinds of conductive inks. Thus, inkjet printing has great potential as a rapid, low-cost, and mask-free fabrication method for ECoG electrodes array on flexible materials [ 32 , 33 , 34 , 35 , 36 ]. We have previously reported a novel method of fabricating thin flexible Parylene-based microelectrode arrays using inkjet printing and silver nanoparticle-based ink for electrokinetic applications [ 37 ].…”