PCB-3D-Printed, Reliable and Reusable Wells for Impedance Spectroscopy of Aqueous Solutions

Abstract

Impedance Spectroscopy (IS) has been shown to be a non-invasive and reliable technique for the electrical characterization of biological materials. This paper presents the design and implementation of reliable, reusable wells that are used to perform IS measurements of aqueous solutions. These reusable wells are detachable, easy to clean and low-cost and they are made up of a platen on a Printed Circuit Board (PCB) and the chambers are manufactured using 3D-printing technology. In this case, in order to verify its functionality, IS measurements of electrolytic and non-electrolytic aqueous solutions were carried out. Initially, as a reference, the impedance spectrum of a Hanks’ solution was obtained following a proposed measurement protocol. Then, we analyse this spectrum and we propose an Equivalent Electrical Model (EEM) for validating the reusable wells. Finally, IS measurements are carried out on aqueous solutions of molecular D-glucose and sodium chloride prepared in Hanks’ solution and deionized water, by considering physiological concentrations. The parameter values of the EEMs of each solution tested were obtained using genetic algorithms and Matlab and, from these values, it is possible to conclude that the measurements performed are unable to differentiate the physiological concentration of glucose in the aqueous solution used. Also, from these results, it can be concluded that the designed wells are suitable for IS measurements of aqueous solutions and that they can be used in Electrical Cell Impedance Sensing (ECIS) or applications that require electrical characterization of solutions.

3D-Printed Sensors and Actuators in Cell Culture and Tissue Engineering: Framework and Research Challenges

“…It is necessary to use biocompatible metals, such as Au or silver, for the electrodes, or biocompatible polymers, such as Polylactic Acid (PLA) or Polyethylene Terephthalate Glycol (PETG) [ 11 ]. Resistance to biodegradation is also important, taking into account the specific objective and duration of the project [ 12 ]. Cell adherence: 3D-printed plates and electrodes should be treated to provide cell adherence, in a similar way as traditional Petri dishes [ 8 ].…”

“…Two-dimensional cell cultures have been traditionally studied with electrical impedance, as previously mentioned, for diverse applications, such as cell toxicity assessment [ 3 ], the study of cell motility [ 4 ], or tissue engineering [ 6 , 7 ]. In the study of impedance spectroscopy measurements of 2D cell cultures, the use of 3D printing technologies for the implementation of a cell culture device is proposed in Cabrera-López et al [ 12 ]. The proposed device is composed of three pieces ( Figure 1 a).…”

“…Acrylonitrile butadiene styrene (ABS) material was used to create this chamber, selected because it is not biodegradable (compared with the most commonly used PLA). Initial experiments were carried out with aqueous solutions [ 12 ] and erythrocytes [ 26 ], with positive results, although electrodes with a lower size were suggested to increase the sensibility to changes of cellular density [ 26 ]. A transparent material on the support piece would also be desirable to visually inspect the cell cultures with a confocal inverted microscope.…”

“…( b ) Photograph of four 3D-printed reusable wells, each one with 1 mL of an aqueous solution. Reproduced from Cabrera-López et al [ 12 ].…”

Effect of Different Selenium Precursors on Structural Characteristics and Chemical Composition of Cu2ZnSnSe4 Nanocrystals

“…2D and 3D printing technologies with nanoinks, based on metal NCs allow to develop printed circuit boards [20][21] and use different semiconductor compounds to design passive and active elements of electronic devices [22][23][24][25][26][27][28][29]. However, nowadays the scienti c and technological challenge is to develop the synthesis procedure of semiconductor NCs with controlled properties and the development of the stable and environmentally friendly colloidal solutions with the required surface tension and viscosity which can be used as inks for printing processes [30][31][32].…”