The suitability of low-cost impedance sensors for microbiological purposes and biofilm growth monitoring was evaluated. The sensors with interdigitated electrodes were fabricated in PCB and LTCC technologies. The electrodes were golden (LTCC) or gold-plated (PCB) to provide surface stability. The sensors were used for monitoring growth and degradation of the reference ATCC 15442 Pseudomonas aeruginosa strain biofilm in invitro setting. During the experiment, the impedance spectra of the sensors were measured and analysed using electrical equivalent circuit (EEC) modelling. Additionally, the process of adhesion and growth of bacteria on a sensor’s surface was assessed by means of the optical and SEM microscopy. EEC and SEM microscopic analysis revealed that the gold layer on copper electrodes was not tight, making the PCB sensors susceptible to corrosion while the LTCC sensors had good surface stability. It turned out that the LTCC sensors are suitable for monitoring pseudomonal biofilm and the PCB sensors are good detectors of ongoing stages of biofilm formation.

In this paper, the electric and thermoelectric properties of thin films of germanium–gold alloy (Ge–Au) are discussed in terms of choosing the optimal deposition process and post-processing conditions to obtain Ge–Au layers with the best thermoelectric parameters. Thin films were fabricated by magnetron sputtering using the Ge–Au alloy target onto glass substrates at two various conditions; during one of the sputtering processes, the external substrate bias voltage (U_b = −150 V) was used. After deposition thin films were annealed in the atmosphere of N₂ at various temperatures (473, 523 and 573 K) to investigate the influence of annealing temperature on the electric and thermoelectric properties of films. Afterwards, the thermocouples were created by deposition of the NiCrSi/Ag contact pads onto Ge–Au films. In this work, particular attention has been paid to thermoelectric properties of fabricated thin films—the thermoelectric voltage, Seebeck coefficient, power factor PF and dimensionless figure of merit ZT were determined.

Miniaturized and integrated analytical devices, including chemical sensors, are at the forefront of modern analytical chemistry. The construction of novel analytical tools takes advantage of contemporary micro- and nanotechnologies, as well as materials science and technology. Two electrochemical techniques were used in experiments: electrochemical impedance spectroscopy and cyclic voltammetry. The goal of this study was to investigate electron transfer resistance in a model solution containing ${\mathrm{Fe}}^{2+/3+}$ ions and protein adsorption using integrated electrochemical cells with different geometry. Tests performed at various ${\mathrm{Fe}}^{2+/3+}$ concentration allowed to verify that these cells work properly. The influence of bovine serum albumin adsorbing to the surface of the integrated electrochemical cells was investigated. In electrochemical impedance spectroscopy, the value of $R_{ct}$ increased with protein adsorption and the relative change of $R_{ct}$ was in range 21% to 55%. In cyclic voltammetry the decreasing amperometric response of the working electrode was used as evidence of protein adsorption on the electrode.

This paper focuses on electron emitters formed using seamless hybrid shaping of the ceramic 3D‐printed cone (as a supporting structure) and a conductive emitting film obtained from the suspension of dispersed carbon nanotubes (CNT). The ceramic cone is post‐process fired to achieve a pure ceramic cone that is coated with emitting CNT mesh film. Meanwhile, a cone‐based polymer emitter is evaluated. The resulting emitter exhibits non‐linear current‐voltage characteristics reaching maximum 0.6 mA anode current with a turn‐on‐field voltage below 1 Vµm⁻¹ and minimal current fluctuation over time. Additionally, the ceramic emitter arrays fabricated using the same technique are demonstrated: if the tip angle and shape in a microscale have tunability in emission is confirmed, meanwhile, the type of volatile gases released during the emission is confirmed using a residual gas analyzer (RGA). The motivation and challenge are to use 3D printing to enable freedom in designing and forming the emitter tip shape and angle and to present the perspective and challenges to use the 3D printing technique combined with the seamless shaping for the CNT mesh film to tune the emitter performance. Especially as this technique and 3D‐printed materials have not been previously employed for electron emitters.

In this article, a near infrared (NIR)‐responsive microscale cantilever made of the novel 3D printable composite based on the ceramic sepiolite and graphene flakes is presented. The developed composite benefits from no necessity to use complex and high‐energy processes and absorbs NIR light and followed by mechanical work, which results in shape transformations of the cantilever. With the irradiation of 1064 nm wavelength, the composite cantilever exhibits the displacement of average—1.3 ± 0.18 mm—with the fast photothermal responsiveness as the laser beam is ON–OFF within 1.7 s. The displacement measurements is based on the video recording using a monochrome camera. Additional to the actuation performance, the material characteristics are presented for the composite and its ingredients including the scanning electron microscope energy dispersive using X­ray analysis, Brunauer–Emmett–Teller, thermogravimetric analysis, and Fourier transform infrared spectroscopy analysis confirming that the addition of the graphene flakes and the ceramic particles to the resin does not change functional groups.