Conventional machining and shaping processes for polymers and elastomers such as injection molding exhibit significant disadvantages, as specific tools have to be manufactured, the method of machining is highly dependent on the material properties, and the cost of automation is usually high. Therefore, additive manufacturing processes (3D printing) have established themselves as an alternative. This eliminates the expensive production of tools and the production is individualized. However, the specific (additive) manufacturing process remains highly dependent on the properties of the material. These processes include selective laser sintering (SLS) for powdered thermoplastic polymers and metals, extrusion such as fused deposition modeling (FDM) for thermoplastic polymers in wire form, or optical curing such as digital light processing (DLP) for liquid resins. Especially for elastomer sensors or circuit boards (structure of several alternately constituted approx. 100 µm-thick elastomer films made with different types of liquid silicone rubber), there is no suitable additive manufacturing process that combines liquid, partly non-transparent source materials, multi-component printing, and very fine layer thicknesses. In order to enable a largely automated, computer-aided manufacturing process, we have developed the concept of ablative multilayer and multi-material laser-assisted manufacturing. Here, the layers (conductive and non-conductive elastomers, as well as metal layers for contacting) are first coated over the entire surface (e.g., spray, dip, or doctor blade coating, as well as galvanic coating) and then selectively removed with a CO₂ or fiber laser. These steps are repeated several times to achieve a multi-layer structured design. Is it not only possible to adjust and improve the work previously carried out manually, but also to introduce completely new concepts, such as fine through-plating between the layers to enable much more compact structures to be possible. As an exemplary application, we have used the process for manufacturing a thin and surface solderable pressure sensor and a stretchable circuit board. Full article

Hybrid electronic materials combine the excellent electronic properties of metals and semiconductors with the mechanical flexibility, ease of processing, and optical transparency of polymers. This talk will discuss hybrids that combine organic and inorganic components at different scales. Metallic and semiconductor nanoparticle cores are coated with conductive polymer shells to create “hybrid inks” that can be inkjet-printed and form conductive leads without any sintering step. Transparent electrodes are printed using ultrathin metal nanowires with core diameters below 2 nm. The chemically synthesized wires spontaneously form percolating structures when patterned with a soft stamp; this rapidly yields optically transparent grid electrodes, even on demanding soft substrates. These new hybrid electronic materials enable the fabrication of soft electronics, including flexible sensors on polymer foils, radio-frequency identification (RFID) antennae on cardboard, and soft human–machine interfaces. Selected devices will be covered at the end of the talk. Full article

A novel gas sensor based on multi-layered graphene (MLG) functionalised with gold nanoparticles (Au-NPs) is presented. We demonstrate for the first time that: (1) the signal saturates during the analyte exposure, something which does not occur in the pristine material and in graphene-based gas sensors in general; (2) the sign of the device current response is inverted. MLG is grown by chemical vapour deposition on pre-patterned CMOS-compatible Mo catalyst. The sensor is fabricated directly on the growth substrate, without any transfer of MLG. The Au-NPs are later deposited from an aerosol on the sensor at a specific controlled location, mitigating any additional patterning steps. The functionalised sensor is tested with 1 ppm (part-per-million) of NO₂ at room temperature. Full article

Ammonia detection at ambient with low-cost sensors is a challenge for various applications like breath analysis and agriculture. Such a challenge can be reached with functionalized SnO₂ based gas sensors using silanization by 3-aminopropyltriethoxysilane (APTES) as an intermediate step before grafting with functional end group providing selectivity for the target gas. Moreover, operation at room temperature gives the opportunity to develop a sensor on a plastic substrate entirely manufactured by inkjet technology, by developing suitable inks, in particular to obtain SnO₂ sensing element. Full article

In this work, we present a novel thermal acoustic gas sensor, fabricated using a CMOS microhotplate and MEMS microphone. The sensing mechanism is based on the detection of changes in the thermal acoustic conversion efficiency which is dependent on the physical properties of the gas. The gas sensor has all the benefits of CMOS technology, including low cost and miniaturization. Here, we demonstrate its application for CO₂ gas detection. Full article

In the Chipscope project funded by the EU, a completely new strategy towards optical microscopy is explored by a team of researchers from different European institutions. In this workshop, the different researchers of the project will explain the last advances obtained in the project, presenting the microscopes, how light emission is produced, and the detection principles and simulations. Full article

This work proposes a portable, software-defined NO₂-sensing platform, which is able to acquire currents ranging from nA to µA from a Single-Walled Carbon Nanotube (SWCNT) gas sensor. It includes an embedded software that steers the system allowing dynamical adjustments of the SWCNT bias levels, measurement range, sampling rate and of measurement time intervals. Further, the embedded functions can post-process the measurement results, log data on an SD card or send data via a wireless connection. Full article

The current technological trends associated with Industry 4.0 and the Internet of Things (IoT) require an interconnected network of sensor nodes providing distributed information on the environment to enable intelligent action to be taken by control systems. Such sensors need to be wireless, self-powered and energy independent. In this work we provide an overview of possible strategies to realize a positive energy balance in autonomous sensor nodes without the use of batteries. We will first overview different sensors in terms of power consumption. We will then concentrate on energy harvesting and storage, showing state-of-the-art possibilities in both cases. Full article

In this work, we present a wearable sensor patch for the early detection of extravasation by using a simple, direct printing process. Interdigitated electrodes are printed on a flexible film, which can be attached to skin. The electrodes are integrated with a top electrode to form a flexible pressure-sensing device utilizing an electrical contact resistance (ECR) variation mechanism. The detector possesses good sensitivity and a low detection limit for pressure variation. By adjusting the printing parameters, sensors of millimeter size can be fabricated and allow the potential for multiple detection points in a large area. In addition, by using silver nanowire inks, the sensor becomes nearly transparent to prevent patients’ panic. The possibility and feasibility of this device for early extravasation detection is also evaluated. Full article

Highly textured Ba_0.5Sr_0.5TiO₃ and Ba_0.6Sr_0.4TiO₃ thin films have been successfully processed using chemical solution deposition (CSD) techniques and annealed at different temperatures to investigate the influence on crystal growth. Microstructure and texture have been evaluated using SEM and XRD techniques. The films showed a homogeneous thickness of ~120 nm and the grain growth seemed to be highly influenced by the annealing temperature. Moreover, by tuning the deposition and annealing conditions, an almost epitaxial growth of Ba_0.6Sr_0.4TiO₃ on the platinized silicon substrate has been achieved. Nevertheless, the samples showed severe cracking due to the strain imposed by the substrate or due to the growing direction. Full article

Low-cost infrared (IR) thermal cameras are powering a rising market of industrial and consumer applications. Complementary metal-oxide-semiconductor (CMOS)-based thermopile arrays are proven thermal imagers that can be monolithically integrated into low-cost and low-power-consumption formats for high-volume manufacturability. Here we present a simple method to evaluate the cross-talk of these arrays and propose a numerical model for device optimization. Full article

Biosensors play a key role in medical diagnostics, and acoustic wave technology such as solidly mounted resonators (SMRs) applied to this field is one of the latest developments with great potential. This study seeks to explore the potential application of SMRs to detect and quantify prostate-specific antigen (PSA) for the screening and diagnosis of prostate cancer. The primary results show promising frequency shift of SMR sensors coated with Polydimethylsiloxane (PDMS) to different liquids. The SMR frequency is 1.082, 1.084 and 1.088 GHz, respectively, to air, deionized water and toluene (liquid) presence. These sensors have great potential as an accurate, low-cost method for measuring PSA and biomarkers for cancer and other diseases. Full article

Standing wave interferometers (SWIs) show enormous potential for miniaturization because of their simple linear optical set-up, consisting only of a laser source, a measuring mirror and two standing wave sensors for obtaining quadrature signals. To reduce optical influences on the standing wave and avoid the need for an exact and long-term stable sensor-to-sensor distance, a single-sensor set-up was developed with a phase modulation by forced oscillation of the measuring mirror. When the correct modulation stroke is applied, the harmonics in the sensor signal can be used for obtaining quadrature signals for phase demodulation and direction discrimination. Full article

We present the feasibility in fabricating membranes and cantilevers made of diamond grown on Si/SiO₂ substrates by femtosecond laser ablation. In the ablation process, we generated nano- and microstructures on the membrane surface. Such laser-induced periodic surface structures (LIPSS) are useful in tailoring the surface chemistry. In combination with wet or reactive ion etching, smooth membranes were generated. Full article

In this paper, metals’ (Cu, Ag, Au)/Al₂O₃/Bi₂Te₃ heterostructures have been fabricated to synergistically optimize their carrier concentration and mobility, thereby enhancing their thermoelectric power factor. Metal can be alloyed with Bi₂Te₃ to reduce the electron concentration. The introduction of the oxide layer further reduces the electron concentration and leads to an increase in mobility. By adjusting the metal and oxide layer, it is possible to realize the simultaneous optimization of electric conductivity and the Seebeck coefficient. This work will enable the optimal and novel design of heterstructures for thermoelectric materials with further improved performance. Full article

Getter materials are technically proven and industrially well-implemented solutions for maintaining a vacuum inside electronic devices to assure long lifetimes and proper operating conditions. The pressure requirements of some hermetically packaged microelectromechanical systems (MEMS) devices, such as gyroscopes, accelerometers, infrared (IR) bolometers, and digital mirrors, are very stringent. The internal pressure can be as low as in the 10⁻³ mbar range. Due to the desorption phenomena of gaseous species from the internal surfaces, the vacuum inside such hermetically sealed electronic devices tends to degrade over time and, in the worst case, can affect the proper operation of the device. The integration of a special nanostructured getter film is an effective way to preserve and guarantee the performance of such devices. In addition to the getter material, there is also the need to develop and customize analytical techniques for post-process vacuum quality control and reliability checks of hermetic bonding, which are extremely important for the assessment of a device’s overall performance, lifetime, and manufacturing process yield. Full article

Current sensing solutions must combine an ultra-low energy consumption trend with high reliability. The challenge lies on a fine setting of the detection threshold with the assurance of a sufficient sensitivity. In this article, the uncertainty introduced on gas sensing applications by the inherent sensor noise is studied. A 1/f model of the electronic noise in polypyrrole-based ammonia (NH₃) sensors is presented and used to estimate the intrinsic signal-to-noise ratio (SNR), giving an effective precision of 10.7 bits, i.e., down to 31.4 ppb in terms of NH₃ concentration. No significant improvement in SNR is achieved by increasing the bias voltage and hence the power consumption. Full article

We report on an inexpensive and very selective gas sensor implemented by simply combining colorimetric indicators casted on top of acetate-based transparent tape, with a commercial microchip adapted here to measure optical reflectance. This sensor can be easily reproduced (leading to quantitatively consistent results), refreshed and reconfigured to sense different target gases replacing only the colorimetric tape. The device may either work as sensor (CO₂ and NH₃) or dosimeter (Formaldehyde) depending on the targeted gas. Full article

The atomic-scale phenomena at surfaces and interfaces influence, and often even dominate, the properties of materials and their functioning in nanoscale devices. This contribution discusses recent results of applying the surface science method, where systems are investigated under idealized conditions. Such experiments directly relate to first-principles calculations and provide insights into mechanisms and processes at a level that cannot be achieved in any other way. The review discusses recent developments with a main emphasis on metal oxides, a versatile and extremely useful class of materials. Full article

We investigate the photoconductivity properties of lead sulphide (PbS) quantum dot ensembles in lithographically tailored gold electrodes with smallest gaps of 15 nm. We demonstrate that quantum dots are reliable nanoscale light/current converters and correlate the measured photocurrents to the quantum dot number, the gap voltage and light irradiance. For the latter, we find a photocurrent power law dependence with an exponent of 2/3. Furthermore, we probe the role of plasmonic effects in the gold electrodes and image by scanning photocurrent microscopy the spatial dependence of photocurrent generation. Full article

We give evidence of the formation of an ordered array of tetra-phenyl porphyrins (TPP) when these molecules are deposited on top of oxygen-passivated Fe(001), namely the Fe(001)-p(1 × 1)O surface. We also prove that they are magnetically coupled with the substrate. The ordered molecular packing, together with the magnetic coupling, are fundamental conditions for application in organic spintronic devices. The system is studied by means of spin-resolved photoemission spectroscopies and scanning tunneling microscopy. Full article

The combination of optics and microfluidics for particle detection makes it possible to fabricate small low-cost devices. In such hybrid-on-chip systems with integrated µLEDs, the particles can be close to the light source, which is beneficial for the detection capability according to the simulation results. In addition, further advantages and extension possibilities of such devices are discussed. Full article

The spectral composition of light has a significant influence on human wellbeing, emotion and health. Natural sunlight is often considered as the ideal light source in this regard. Therefore, artificial lighting solutions that mimic natural sunlight are a central research topic in the lighting industry. Another global trend is the monitoring and evaluation of the vital parameters of human beings to improve their health status and their personal lifestyle. Here, we present VitaLight, a laboratory sample for a smart lighting system that aims to interconnect these global trends and consists of VitaWatch, a wristband with functionally integrated sensors that is comfortable to wear on the body, and VitaLUMI, a lighting unit with access to the internet. Full article

We investigate the dielectric properties of homovalent (M⁴⁺)-doped Ba(Ti_1−xM_x)O₃ compositions using a two-dimensional Ising-like network. The model is mainly based on the interaction of permanent and induced dipoles and allows us to simulate the collective behavior of atoms at finite temperatures. In contrast to previous publications, we also include first-principles calculations to model the local environment and interaction of the B-site atoms. Furthermore, in order to describe the corresponding physics more accurately, we introduce an additional degree of freedom for the polarization direction. Our simulations provide an insight into the formation of polar clusters, the evolution of spontaneous polarization at different concentrations of dopants, and the response to external fields. For the purpose of studying the dielectric properties, the model is used to calculate hysteresis curves and related quantities. Full article

This work simulates the collapse of a spherical void in pure Sn during melting using molecular dynamics (MD). Simulations were performed for two temperatures with a modified embedded atom method (MEAM) potential, which was reported to be in good agreement with respect to melting point and elastic constants. Solutions of the Rayleigh–Plesset (RP) equation are used for comparison under the assumption of macroscopic surface tension and liquid viscosity. Despite a qualitative correlation, longer collapse times were observed in MD simulations, which arose from partial solid structures and the incubation time for melting. Full article

Graphene- and carbon nanotube (CNT)-based inks have been printed on relevant heat sink materials by Aerosol jet. The thickness of the layers varied between ~100 and ~1.500 nm. The inks’ viscosity ranged from <20 up to 600 cps at a solid content between 0.18 and 3% and wide particle sizes from 5 nm up to 5 µm. The printed layers could be interesting for rather high-power and high-temperature applications including thermal heat spreaders, resistive heaters, high-current carrying interconnectors, temperature sensors and ordnance fuze technology. Full article

Pillar-shaped Gallium arsenide (GaAs) micromechanical resonators are fabricated, and the feasibility to measure the inside of the pillars in the axial direction with laser-induced GHz ultrasound based on picosecond ultrasonics is tested. Measurements on the pillars with head sizes in the µm range show excellent agreement with theoretical predictions. Full article

Our contribution focuses on a correlative study of polyaniline (PANI) electropolymerisation and UV/VIS spectroscopy. PANI was prepared via electro-oxidation using a potentiodynamic method on commercial gold screen-printed electrodes (Au-SPE). By using an in-situ spectroelectrochemical method, the development of the polymer was observed from monomer, monomer oxidation to final polymer formation and its transformations between the oxidation forms. The results confirm the spontaneous doping of the polymer during the polymerisation, the instability of leucoemeraldine form in air and its two-stage oxidation to emeraldine form. The final conductive PANI deposited on Au-SPE will be used as sensor element for the detection of toxic organic compounds. Full article

We performed endohedral functionalization of high-purity metallicity-sorted semiconducting and metallic single-walled carbon nanotubes (SWCNTs) with a mean diameter of 1.4 nm with silver chloride (AgCl) by the method of capillary filling with the melt. The AgCl-filled SWCNTs were investigated by high-resolution scanning transmission electron microscopy and spectroscopic techniques, such as Raman spectroscopy, X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy, which were combined to study comprehensively the modified electronic properties of the filled SWCNTs. The data revealed a downshift of the Fermi level of the nanotubes upon filling, i.e., a p-doping of SWCNTs. Full article

The focus of this work lies on investigations on a new Nano Fabrication Machine (NFM-100) with a mounted atomic force microscope (AFM). This installed tip-based measuring system uses self-sensing and self-actuated microcantilevers, which can be used especially for field-emission scanning probe lithography (FESPL). The NFM-100 has a positioning range of Ø 100 mm, which offers, in combination with the tip-based measuring system, the possibility to analyse structures over long ranges. Using different gratings, the accuracy and the reproducibility of the NFM-100 and the AFM-system will be shown. Full article

We present technological issues in the deposition of diamond films on gallium nitride (GaN) membranes. Many wrinkles and thicker diamond layers were observed at the membrane center and poor quality diamond outside the membrane area. The deflection of the membranes was analyzed by a bulging method using white light interferometry. The membrane bending is discussed in the terms of temperature gradient and mismatch of thermal expansion coefficients of materials. Full article

In this work, the fabrication of composites consisting of piezoelectric ZnO ceramic nanostructures and nanocellulose fillers in a UV-cured acrylic matrix has been exploited for the design of new functional coatings for green energy generation. The piezoelectric behavior was investigated at different accelerations applied to cantilever beams. The piezoelectric signal generated by the different ZnO nanostructures was improved by aluminum nitride film integration on the beam and proof mass insertion at the tip. Full article

Gas sensitive iridium-gated field effect transistors based on silicon carbide were used to study the response towards formaldehyde, ammonia, carbon monoxide and nitrogen dioxide at concentrations ranging from parts per million to parts per billion diluted in dry synthetic air and under 50% of relative humidity. The sensor performance was studied using temperature cycled operation mode from 270 to 390 °C to investigate the capability of these devices to discriminate between the studied gases under different background conditions via pattern recognition algorithms. Full article

In this paper, we present two approaches to synthesize nanostructured metal oxide semiconductors in a form of multi-layer thin films later assembled as a conductometric gas-sensors. The first approach produces a combination of thin solid film of tungsten trioxide (WO₃) with nanoclusters of cupric oxide (CuO) prepared by a magnetron-based gas aggregation cluster source (GAS). The second method is a two-step reactive magnetron sputtering forming a nanostructured copper tungstate (CuWO₄) on-top of a WO₃ film. Both methods lead to synthesis of nanosized hetero-junctions. These greatly improve the sensorial response to hydrogen in comparison with a WO₃ thin film alone. Full article

We investigated the optoelectronic properties of lead sulphide (PbS) quantum dot films in lithographically tailored gold nanogap electrodes. In particular, we aimed at the correlated measurement of photoconductivity and luminescence as a tool to characterize the charge dynamics from exciton generation to carrier extraction and recombination. Combining these measurements in an optical microscope with laser scanning excitation enabled, as well, the spatially resolved observation of the involved effects. Full article

Plasmonic heating finds multiple applications in cell manipulation and stimulation, where heat generated by metal nanoparticles can be used to modify cell adhesion, control membrane currents, and suppress neuronal action potentials among others. Metal nanoparticles can also be easily integrated in artificial extracellular matrices to provide tunable, thermal cueing functionalities with nanometer spatial resolution. In this contribution, we present a platform enabling the combination of plasmonic heating with localized temperature sensing using quantum dots (QDs). Specifically, a functional nanocomposite material was designed with gold nanorods (AuNRs) and QDs incorporated in a cell-permissive hydrogel (e.g., collagen) as well as an optical set-up combining optical heating and temperature imaging, respectively. Specific area stimulation/readout can be realized through structured illumination using digital micromirror device (DMD) projection. Full article

In order to investigate the necessary device improvements for high-temperature CO sensing with SiC metal insulator semiconductor field effect transistor (MISFET)-based chemical gas sensors, devices employing, as the gas-sensitive gate contact, a film of co-deposited Pt/Al₂O₃ instead of the commonly used catalytic metal-based contacts were fabricated and characterized for CO detection at elevated temperatures and different CO and O₂ levels. It can be concluded that the sensing mechanism at elevated temperatures correlates with oxygen removal from the sensor surface rather than the surface CO coverage as observed at lower temperatures. The long-term stability performance was also shown to be improved compared to that of previously studied devices. Full article

We present a novel approach to perform passive visible light sensing of retroreflective foils mounted on a moving object by utilizing low-cost hardware combined with a self-developed, low complex software algorithm with minimal training effort for successful classification. Therewith, we show the feasibility of utilizing the visible light spectrum not only for illumination, but also to perform sensing tasks, which consequently will lead to less energy consumption, no need for active sensors on the moving object, and finally no necessity of wireless radio frequency communication between the object and the processing device. Full article

In this paper, we report on the optimization of SnO₂-based thin film gas sensor devices by mono-, bi- and trimetallic nanoparticles. Ag, AgRu, and AgRuPd nanoparticles are sputter deposited on CMOS-integrated SnO₂-thin film gas sensor devices. The CMOS device is a worldwide unique chip containing an array of eight microhotplates. The response towards the target gas CO was dramatically increased from 10% to more than 70% by using trimetallic AgRuPd nanoparticles. Full article

Thin organic films are widely used in sensors, solar cells, and optical devices due to their intense absorption in the visible/near-infrared (IR) region. Shifting, quenching, or reshaping of some spectral features can be achieved by chemical functionalization of the molecules, whereas an anisotropic fingerprint due to preferential molecular alignment can be induced via a proper design and/or preparation of the substrate. Recently, we investigated the optical response of thin films of porphycene to acidification. With respect to the well-known and closely related tetraphenyl porphyrin, porphycene has the clear advantage of being optically active in the full visible range, and this makes visible by naked eye the immediate change of the film from brilliant blue-turquoise to green when exposed to HCl vapors. In this work, by exploiting a homemade reflectance anisotropy spectroscopy (RAS) apparatus, we explore possible optical anisotropies in the visible spectral range of porphycene films and relate them to the film morphology analyzed by atomic force microscopy (AFM). Full article