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The paper reports on fabrication processes related to low-cost manufacturing and integration of microfluidic biomedical detection systems fabricated without a cleanroom. First, we developed and demonstrated a process for manufacturing a microfluidic device. Second, we demonstrated a low temperature assembly technique for the packaging of the surface acoustic wave (SAW) sensor die. Sequentially, we demonstrated a low temperature process for the integration of the microfluidic device with a SAW sensor to form a fully functional biomedical detection system. The microfluidic device was manufactured by mechanical micromilling technology that is rapid, conceptually simple and a low-cost process. It is suitable for both prototyping and for a low and a medium scale production to address a niche market that is typical for the intended application. That technology has no specific requirement for a certified clean room environment. Unlikely other technology, such as molding and photolithography, for example, it has a shorter lead-time from design to manufacturing. The assembly technique for a SAW sensor is a carefully selected combination of known and matured processing steps causing no damage to a sensitive biofunctionalization on the sensor. The developed and demonstrated integration process for the in-house manufactured microfluidic device and the SAW sensor is a purely low temperature process that prevents a biological material deposited on the SAW sensor from degradation. Biocompatibility issues were also addressed during the study reported. Finally, we performed an ultrasonic (US) impedance characterization of the fully assembled system and demonstrated that neither the microfluidic system integrated on the sensor nor the integration process itself have an impact on the US impedance of the SAW sensor. That means that it does not affect the sensor performance.

The EuNetAir Joint Exercise focused on the evaluation and assessment of environmental gaseous, particulate matter (PM) and meteorological microsensors versus standard air quality reference methods through an experimental urban air quality monitoring campaign. This work presents the second part of the results, including evaluation of parameter dependencies, measurement uncertainty of sensors and the use of machine learning approaches to improve the abilities and limitations of sensors. The results confirm that the microsensor platforms, supported by post processing and data modelling tools, have considerable potential in new strategies for air quality control. In terms of pollutants, improved correlations were obtained between sensors and reference methods through calibration with machine learning techniques for CO (r = 0.13–0.83), NO (r = 0.24–0.93), O (r = 0.22–0.84), PM10 (r = 0.54–0.83), PM2.5 (r = 0.33–0.40) and SO (r = 0.49–0.84). Additionally, the analysis performed suggests the possibility of compliance with the data quality objectives (DQO) defined by the European Air Quality Directive (2008/50/EC) for indicative measurements.

We present a (1-D) SCAPS device model to address the following: (i) the surface passivation mechanisms (i.e.field-effect and chemical), (ii) their impact on the CIGS solar cell performance for varying CIGS absorberthickness, (iii) the importance of fixed charge type (+/−) and densities of fixed and interface trap charges, and(iv) the reasons for discrete gains in the experimental cell efficiencies (previously reported) for varying CIGSabsorber thickness. First, to obtain a reliable device model, the proposed set of parameters is validated for bothfield-effect (due to fixed charges) and chemical passivation (due to interface traps) using a simple M-I-S teststructure and experimentally extracted values (previously reported) into the SCAPS simulator. Next, we providefigures of merits without any significant loss in the solar cell performances for minimum net −Qf and maximumacceptable limit for Dit, found to be ∼5 × 1012 cm−2 and ∼1 × 1013 cm−2 eV−1 respectively. We next showthat the influence of negative fixed charges in the rear passivation layer (i.e. field-effect passivation) is morepredominant than that of the positive fixed charges (i.e. counter-field effect) especially while considering ultrathin(<0.5 μm) absorber layers. Furthermore, we show the importance of rear reflectance on the short-circuitphotocurrent densities while scaling down the CIGS absorber layers below 0.5 μm under interface chemical andfield-effect passivation mechanisms. Finally, we provide the optimal rear passivation layer parameters for efficienciesgreater than 20% with ultra-thin CIGS absorber thickness (<0.5 μm). Based on these simulation results,we confirm that a negatively charged rear surface passivation with nano-point contact approach is efficient forthe enhancement of cell performances, especially while scaling down the absorber thickness below 0.5 μm.

We present a (1-D) SCAPS device model to address the following: (i) the surface passivation mechanisms (i.e.field-effect and chemical), (ii) their impact on the CIGS solar cell performance for varying CIGS absorberthickness, (iii) the importance of fixed charge type (+/−) and densities of fixed and interface trap charges, and(iv) the reasons for discrete gains in the experimental cell efficiencies (previously reported) for varying CIGSabsorber thickness. First, to obtain a reliable device model, the proposed set of parameters is validated for bothfield-effect (due to fixed charges) and chemical passivation (due to interface traps) using a simple M-I-S teststructure and experimentally extracted values (previously reported) into the SCAPS simulator. Next, we providefigures of merits without any significant loss in the solar cell performances for minimum net −Qf and maximumacceptable limit for Dit, found to be ∼5 × 1012 cm−2 and ∼1 × 1013 cm−2 eV−1 respectively. We next showthat the influence of negative fixed charges in the rear passivation layer (i.e. field-effect passivation) is morepredominant than that of the positive fixed charges (i.e. counter-field effect) especially while considering ultrathin(<0.5 μm) absorber layers. Furthermore, we show the importance of rear reflectance on the short-circuitphotocurrent densities while scaling down the CIGS absorber layers below 0.5 μm under interface chemical andfield-effect passivation mechanisms. Finally, we provide the optimal rear passivation layer parameters for efficienciesgreater than 20% with ultra-thin CIGS absorber thickness (<0.5 μm). Based on these simulation results,we confirm that a negatively charged rear surface passivation with nano-point contact approach is efficient forthe enhancement of cell performances, especially while scaling down the absorber thickness below 0.5 μm.

We present a (1-D) SCAPS device model to address the following: (i) the surface passivation mechanisms (i.e.field-effect and chemical), (ii) their impact on the CIGS solar cell performance for varying CIGS absorberthickness, (iii) the importance of fixed charge type (+/−) and densities of fixed and interface trap charges, and(iv) the reasons for discrete gains in the experimental cell efficiencies (previously reported) for varying CIGSabsorber thickness. First, to obtain a reliable device model, the proposed set of parameters is validated for bothfield-effect (due to fixed charges) and chemical passivation (due to interface traps) using a simple M-I-S teststructure and experimentally extracted values (previously reported) into the SCAPS simulator. Next, we providefigures of merits without any significant loss in the solar cell performances for minimum net −Qf and maximumacceptable limit for Dit, found to be ∼5 × 1012 cm−2 and ∼1 × 1013 cm−2 eV−1 respectively. We next showthat the influence of negative fixed charges in the rear passivation layer (i.e. field-effect passivation) is morepredominant than that of the positive fixed charges (i.e. counter-field effect) especially while considering ultrathin(<0.5 μm) absorber layers. Furthermore, we show the importance of rear reflectance on the short-circuitphotocurrent densities while scaling down the CIGS absorber layers below 0.5 μm under interface chemical andfield-effect passivation mechanisms. Finally, we provide the optimal rear passivation layer parameters for efficienciesgreater than 20% with ultra-thin CIGS absorber thickness (<0.5 μm). Based on these simulation results,we confirm that a negatively charged rear surface passivation with nano-point contact approach is efficient forthe enhancement of cell performances, especially while scaling down the absorber thickness below 0.5 μm.