In this paper we report on the optimization of an amplification mechanism to enable large displacements in microelectromechanical systems (MEMS). As a case study, we considered a MEMS-based platform for the mechanical testing of nanomaterials, but the results we obtained can be extended to other devices, too. The studied device consists of a couple of V-shaped thermal actuators, heat sink beams, comb drives for sensing the displacements delivered by the actuators to the sample to be tested, and an amplification stage capable of amplifying the produced displacements to tens of micrometers. Regarding the amplification stage, three different schemes were designed and simulated in order to identify the optimal solution. To this aim, static structural analyses have been carried out to predict the performance of the amplification mechanism with respect to geometrical parameters, such as inclination angle, length or width of the beams embedded in the amplification stage. An amplification factor as large as 50 is found. The numerical results show good agreement with those obtained from analytical models. The performance of the complete device is also evaluated through 3D steady-state static thermal-electrical analyses under variable voltage applied to the actuators.

We present a fabrication process for the production of 3-dimensional micro-structured polymeric films. The microstructures are fabricated in a single step using thermal nanoimprint lithography as patterning technique. The micro-structured polymer films are then transformed into a 3D shape by means of a plug-assisted thermoforming process, while keeping the functionality of the micro-patterned areas. The preserved functionality is characterized by water contact angle measurements, while the deformation of the micro-structured topographies due to the thermoforming process is analyzed using confocal microscopy and Digital Image Correlation (DIC) techniques. This combined fabrication process represents a promising solution to complement in-mold decoration approaches, enabling the production of new functional surfaces. As the microstructures are fabricated by means of a mechanical modification of the surface, without the need of chemical treatments or coatings, the presented technique represents a promising, simple and green solution, suitable for the industrial fabrication of 3D nonplanar shaped functional surfaces. • A method to produce 3-dimensional micro-structured polymeric films by combination of nanoimprint lithography and thermoforming is presented • The surface microstructures defined by Nanoimprint Lithography induce surface hydrophobicity which is maintained after the thermoforming process. The microstructures defined by nanoimprint induce surface hydrophobicity which is maintained after the thermoforming process. • The strain induced by the thermoforming process deforms the microstructure, affecting the functional properties. • This combined process complement in-mold decoration approaches with the introduction of new functional surfaces.

Rare cells such as circulating tumor cells and prenatal fetal cells can be captured by size-dependent filtration using a microfluidic device. Herein, we report a method to release the captured cells with the same microfluidic device which consisted of a microfabricated filter with tapered holes. When a cell containing flow passed through the filter, the cells could be blocked by the filter. Afterward, a reverse flow was applied to release the captured cells. To increase the efficiency of the capture and the release, a filter with tapered holes was used and micro-particles of sizes between smaller and large hole diameters were added into the reverse flow. We found that when the majority of the holes were blocked, the trans-filter flow resistance drastically increased and most of the captured cells could be released. As a proof of concept, ovarian cancer cells SKOV3 were used, showing a high release efficiency and remarkable viability of the collected cells. • Development of a method to release the rare cells captured by a filter with tapered holes. • Calculation of the trans-filter pressure as a function of percentage of blocked holes. • Demonstration of the capture and release at high efficiency. • Demonstration of a high viability of the cells collected after capture and release.

Most formulations of metal inks comprise of a suspension of nanoparticles however, these suffer when printed by the formation of unwanted agglomeration. The exploration and optimisation of particle-free silver-complex ink is causing a strong demand for inkjet printing of these formulations over nanoparticle-based suspension inks. This is due to the enhanced printability and rapid conversion via thermal reduction into a conductive material, which can be utilised in electronics manufacture. We developed a silver-complex ink for ‘smart-clothing’ through inkjet printing. The high-quality printing - characterised by no satellite droplet formation and fast speed - is demonstrated upon polyester fabric by the formation of electrical circuitry using a thermal reduction process. Fabric printing is limited by good metal coverage and adhesion, which we demonstrate and improve on in the work by the application of a low temperature, atmospheric air plasma pre-treatment to the polyester surface, which improves printed silver density and coverage using a plasma device which is easy to operate and economic. Printed silver layer reduction and film crystallinity is characterised from high resolution scanning electron microscopy, and spectroscopy (Ultraviolet-visible and Raman) detailing growth mechanisms for high track feature conductivity, producing a low sheet resistivity of 1.378 ± 0.001 Ω/□ and by the lighting of a 1.9 V, 250 mA Light Emitting Device, highlighting its application for conductive features processing. • Conductive films on PET fabric. • Ink jet printing particle-free silver-complex ink. • Conductive thin Ag films, 1.378 ± 0.001 Ω/□. • Enhancement of printed density and coverage by atmospheric plasma pre-treatment.