3D printing scanning electron microscopy sample holders: A quick and cost effective alternative for custom holder fabrication

The Current Shortcomings and Future Possibilities of 3D Printed Electrodes

3D printing has changed many industries and research areas, and it is poised to do the same for electrochemistry and electroanalytical sciences. The ability to easily shape electrically conductive parts in complex geometries, something very difficult to do using traditional manufacturing techniques, can now be easily accomplished at home, opening the possibility of fabricating electrodes and electrochemical cells with geometries that were once unimaginable. This ability can be a milestone in electrochemistry, allowing the fabrication of systems tailored to specific applications. Unfortunately, this is not what is seen to date, with 3D printing mostly reproducing "traditional" designs, using little of the "freedom of design" promised by the technology. We reason that these results come from too much focus on reproducing the electrochemical behavior of metallic electrodes instead of understanding how material properties impact the performance of 3D printed electrodes and working within these constraints. 3D printing will change electrochemistry and electroanalytical sciences if we understand and learn to work with its limitations.

Challenges faced with 3D-printed electrochemical sensors in analytical applications

Prototyping analytical devices with three-dimensional (3D) printing techniques is becoming common in research laboratories. The attractiveness is associated with printers' price reduction and the possibility of creating customized objects that could form complete analytical systems. Even though 3D printing enables the rapid fabrication of electrochemical sensors, its wider adoption by research laboratories is hindered by the lack of reference material and the high "entry barrier" to the field, manifested by the need to learn how to use 3D design software and operate the printers. This review article provides insights into fused deposition modeling 3D printing, discussing key challenges in producing electrochemical sensors using currently available extrusion tools, which include desktop 3D printers and 3D printing pens. Further, we discuss the electrode processing steps, including designing, printing conditions, and post-treatment steps. Finally, this work shed some light on the current applications of such electrochemical devices that can be a reference material for new research involving 3D printing.

Automated device for continuous stirring while sampling in liquid chromatography systems

Ultra-performance liquid chromatography is a common analysis tool, and stirring is common in many laboratory setups. Here we show a device which enables continuous stirring of samples whilst inside an ultra-performance liquid chromatography system. Utilizing standard magnetic stirring bars that fit standard vials, the device allows for the automation of experimental setups that require stirring. The device is designed such that it can replace the standard sample holder and fits in its place, while being battery operated. The use of three-dimensional (3D) printing and commercially available parts enables low-effort and low-cost device production, as well as easy modifications. Testing the device was performed by video analysis and by following the kinetics of a dynamic combinatorial library that is known to be exquisitely sensitive to agitation, as a result of involving a fiber growth-breakage mechanism. Design files and schematics are provided.

3D Printed Graphene Electrodes' Electrochemical Activation

Three-dimensional (3D) printing technologies are emerging as an important tool for the manufacturing of electrodes for various electrochemistry applications. It has been previously shown that metal 3D electrodes, modified with metal oxides, are excellent catalysts for various electrochemical energy and sensing applications. However, the metal 3D printing process, also known as selective laser melting, is extremely costly. One alternative to metal-based electrodes for the aforementioned electrochemical applications is graphene-based electrodes. Nowadays, the printing of polymer-/graphene-based electrodes can be carried out in a matter of minutes using cheap and readily available 3D printers. Unfortunately, these polymer/graphene electrodes exhibit poor electrochemical activity in their native state. Herein, we report on a simple activation method for graphene/polymer 3D printed electrodes by a combined solvent and electrochemical route. The activated electrodes exhibit a dramatic increase in electrochemical activity with respect to the [Fe(CN)₆]^4-/3- redox couple and the hydrogen evolution reaction. Such in situ activation can be applied on-demand, thus providing a platform for the further widespread utilization of 3D printed graphene/polymer electrodes for electrochemistry.

3D-Printed Biosensor Arrays for Medical Diagnostics

While the technology is relatively new, low-cost 3D printing has impacted many aspects of human life. 3D printers are being used as manufacturing tools for a wide variety of devices in a spectrum of applications ranging from diagnosis to implants to external prostheses. The ease of use, availability of 3D-design software and low cost has made 3D printing an accessible manufacturing and fabrication tool in many bioanalytical research laboratories. 3D printers can print materials with varying density, optical character, strength and chemical properties that provide the user with a vast array of strategic options. In this review, we focus on applications in biomedical diagnostics and how this revolutionary technique is facilitating the development of low-cost, sensitive, and often geometrically complex tools. 3D printing in the fabrication of microfluidics, supporting equipment, and optical and electronic components of diagnostic devices is presented. Emerging diagnostics systems using 3D bioprinting as a tool to incorporate living cells or biomaterials into 3D printing is also reviewed.