scholarly journals Fully printed origami thermoelectric generators for energy-harvesting

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Andres Georg Rösch ◽  
André Gall ◽  
Silas Aslan ◽  
Matthias Hecht ◽  
Leonard Franke ◽  
...  

AbstractEnergy-harvesting from low-temperature environmental heat via thermoelectric generators (TEG) is a versatile and maintenance-free solution for large-scale waste heat recovery and supplying renewable energy to a growing number of devices in the Internet of Things (IoT) that require an independent wireless power supply. A prerequisite for market competitiveness, however, is the cost-effective and scalable manufacturing of these TEGs. Our approach is to print the devices using printable thermoelectric polymers and composite materials. We present a mass-producible potentially low-cost fully screen printed flexible origami TEG. Through a unique two-step folding technique, we produce a mechanically stable 3D cuboidal device from a 2D layout printed on a thin flexible substrate using thermoelectric inks based on PEDOT nanowires and a TiS2:Hexylamine-complex material. We realize a device architecture with a high thermocouple density of 190 per cm² by using the thin substrate as electrical insulation between the thermoelectric elements resulting in a high-power output of 47.8 µWcm−² from a 30 K temperature difference. The device properties are adjustable via the print layout, specifically, the thermal impedance of the TEGs can be tuned over several orders of magnitudes allowing thermal impedance matching to any given heat source. We demonstrate a wireless energy-harvesting application by powering an autonomous weather sensor comprising a Bluetooth module and a power management system.

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Andreas Albrecht ◽  
Almudena Rivadeneyra ◽  
Marco Bobinger ◽  
Jacopo Bonaccini Calia ◽  
Florin C. Loghin ◽  
...  

This work presents a comparative analysis of materials for planar semitransparent thermocouples fabricated by spray deposition on a flexible substrate. Three different materials are employed to build such devices, analyzing also the effect of the spray order in their final performance. The highest Seebeck coefficient (50.4 μV/K) is found for a junction made of carbon nanotubes (CNTs) on top of silver nanowires (AgNWs) whereas its efficiency in terms of power is the lowest because of the higher sheet resistance of the CNTs. In this case, the best combination for energy-harvesting purposes would be poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and AgNWs, with a power factor of 219 fW/K2. These results prove the feasibility of developing large-scale and cost-effective thermocouples that could be used for sensing or energy-harvesting applications.


Author(s):  
Shancy Augustine ◽  
Pan Gu ◽  
Xiangjun Zheng ◽  
Toshikazu Nishida ◽  
Z. Hugh Fan

There is a need for low-cost immunoassays that measure the presence and concentration of multiple harmful agents in one device. Currently, comparable immunoassays employ a one-analyte-per-test format that is time consuming and not cost effective for the requirement of detecting multiple analytes in a single sample. For instance, if a spectrum of harmful agents, including E. coli O157, cholera toxin, and Salmonella typhimurium, should be simultaneously monitored in foods and drinking water, then a one-analyte-per-test would be inefficient. This work demonstrates a platform capable of simultaneous detection of multiple analytes in a single, low-cost, microvalve array-enabled multiplexed immunoassay. This multiplexed immunoassay platform is demonstrated in a prototype COC (cyclic olefin copolymer) device with a 2×3 array in which 6 analytes can be detected simultaneously. In order to contain and regulate the flow of reagents in the multichannel device, an array of microfluidic valves actuated by a thermally expandable material and microfabricated resistors have been developed to direct the flow to the necessary assay sites. The microvalve-based immunoassay is shown to be reliable, easy to operate, and compatible with large-scale integration. The all-plastic microvalves use paraffin wax as the thermally sensitive material which drastically reduces power consumption by latching upon closing so that pulsed power is required only to close and latch the microvalve until it is necessary to re-open the valve. The multiplexed detection scheme has been demonstrated by using three proteins, C reactive protein (CRP) and transferrin, both of which are biomarkers associated with traumatic brain injury (TBI) as well as bovine serum albumin (BSA) as the negative control. Since there are no external bulky pneumatic accessories required to operate/latch the microvalves in the device, this compact, thermally actuated and latching microvalve-enabled multiplexed immunoassay has the potential to realize a portable, low power, battery operated microfluidic device for biological assays.


2021 ◽  
Author(s):  
Stéphane Chevaliez ◽  
Françoise Roudot-Thoraval ◽  
Christophe Hézode ◽  
Jean-Michel Pawlotsky ◽  
Richard Njouom

Aim: HCV diagnosis will become the bottleneck in eliminating hepatitis C. Simple, accurate and cost-effective testing strategies are urgently needed to improve hepatitis C screening and diagnosis. Materials & methods: Performance of seven rapid diagnostic tests (RDT) have been assessed in a large series (n = 498) of serum or plasma specimens collected in France and in Cameroon. Results: Specificity varied from 96.1 to 100%. The clinical sensitivity, compared with immunoassays as the reference, was high for all seven RDT (97.2–100%). The Multisure HCV antibody assay and OraQuick HCV rapid antibody test reached sensitivity ≥99%. Conclusion: A number of RDT may be suitable for WHO prequalification and may be implemented in the framework of large-scale low-cost treatment programs to achieve the WHO viral hepatitis objectives by 2030.


Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 148 ◽  
Author(s):  
Francisco J. Romero ◽  
Almudena Rivadeneyra ◽  
Markus Becherer ◽  
Diego P. Morales ◽  
Noel Rodríguez

In this paper, we present a simple, fast, and cost-effective method for the large-scale fabrication of high-sensitivity humidity sensors on flexible substrates. These sensors consist of a micro screen-printed capacitive structure upon which a sensitive layer is deposited. We studied two different structures and three different sensing materials by modifying the concentration of poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT:PSS) in a graphene oxide (GO) solution. The results show that the aggregation of the PEDOT:PSS to the GO can modify its electrical properties, boosting the performance of the capacitive sensors in terms of both resistive losses and sensitivity to relative humidity (RH) changes. Thus, in an area less than 30 mm2, the GO/PEDOT:PSS-based sensors can achieve a sensitivity much higher (1.22 nF/%RH at 1 kHz) than other similar sensors presented in the literature which, together with their good thermal stability, time response, and performance over bending, demonstrates that the manufacturing approach described in this work paves the way for the mass production of flexible humidity sensors in an inexpensive way.


2020 ◽  
Vol 12 (21) ◽  
pp. 9158
Author(s):  
Xiaomiao Tan ◽  
Jiangyu Zhu ◽  
Minato Wakisaka

The development of efficient, environmentally friendly, low-cost approaches used to boost the growth of microalgae is urgently required to meet the increasing demands for food supplements, cosmetics, and biofuels. In this study, the growth promotion effects of protocatechuic acid (PCA) in the freshwater microalga Euglena gracilis were confirmed for the first time. PCA is a simple phenolic compound derived from natural plants and has a range of biological functions. The highest biomass yield, 3.1-fold higher than that of the control, used at 1.3 g·L−1, was obtained at 800 mg·L−1 of PCA. The yields of the metabolites chlorophyll a, carotenoids, and paramylon in the presence of PCA at 800 mg·L−1 were 3.1, 3.3, and 1.7 times higher than those of the control group, respectively. The highest paramylon yield was achieved at a lower dosage of PCA (100 mg·L−1), which is considered to be feasible for economic paramylon production. The growth and biosynthesis of metabolites stimulated by phytochemicals such as PCA could be an efficient and cost-effective strategy to enhance the productivity of microalgae in large-scale cultivations.


2020 ◽  
Vol 6 ◽  
pp. 205520762093644
Author(s):  
Ben Ainsworth ◽  
Anne Bruton ◽  
Mike Thomas ◽  
Lucy Yardley

Digital behaviour change interventions can provide effective and cost-effective treatments for a range of health conditions. However, after rigorous evaluation, there still remain challenges to disseminating and implementing evidence-based interventions that can hinder their effectiveness ‘in the real world’. We conducted a large-scale randomised controlled trial of self-guided breathing retraining, which we then disseminated freely as a digital intervention. Here we share our experience of this process after one year, highlighting the opportunities that digital health interventions can offer alongside the challenges that must be addressed in order to harness their effectiveness. Whilst such treatments can support many individuals at extremely low cost, careful dissemination strategies should be proactively planned in order to ensure such opportunities are maximised and interventions remain up to date in a fast-moving digital landscape.


2019 ◽  
Vol 117 (4) ◽  
pp. 317-322
Author(s):  
Michael G Just ◽  
Steven D Frank

AbstractTree-stem growth is an important metric for evaluating many ecological and silvicultural research questions. However, answering these questions may require monitoring growth on many individual trees that span changing environments and geographies, which can incur significant costs. Recently, citizen science has been successfully employed as a cost-effective approach to collect data for large-scale projects that also increases scientific awareness. Still, citizen-science-led tree-growth monitoring requires the use of tools that are affordable, understandable, and accurate. Here, we compare an inexpensive, easy-to-install dendrometer band to two other bands that are more expensive with more complex installations. We installed a series of three dendrometers on 31 red maples (Acer rubrum) in two urban areas in the eastern United States. We found that the stem-growth measurements reported by these dendrometers were highly correlated and, thus, validate the utility of the inexpensive band.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1879
Author(s):  
Aniello Falco ◽  
Francisco J. Romero ◽  
Florin C. Loghin ◽  
Alina Lyuleeva ◽  
Markus Becherer ◽  
...  

This work demonstrates a cost-effective manufacturing method of flexible and fully printed microheaters, using carbon nanotubes (CNTs) as the heating element. Two different structures with different number of CNT layers have been characterized in detail. The benchmarking has been carried out in terms of maximum operating temperature, as well as nominal resistance and input power for different applied voltages. Their performances have been compared with previous reports for similar devices, fabricated with other technologies. The results have shown that the heaters presented can achieve high temperatures in a small area at lower voltages and lower input power. In particular, the fully printed heaters fabricated on a flexible substrate covering an area of 3.2 mm2 and operating at 9.5 V exhibit a maximum temperature point above 70 °C with a power consumption below 200 mW. Therefore, we have demonstrated that this technology paves the way for a cost-effective large-scale fabrication of flexible microheaters aimed to be integrated in flexible sensors.


Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5558
Author(s):  
Dimitra Vernardou ◽  
Charalampos Drosos ◽  
Andreas Kafizas ◽  
Martyn E. Pemble ◽  
Emmanouel Koudoumas

The need for clean and efficient energy storage has become the center of attention due to the eminent global energy crisis and growing ecological concerns. A key component in this effort is the ultra-high performance battery, which will play a major role in the energy industry. To meet the demands in portable electronic devices, electric vehicles, and large-scale energy storage systems, it is necessary to prepare advanced batteries with high safety, fast charge ratios, and discharge capabilities at a low cost. Cathode materials play a significant role in determining the performance of batteries. Among the possible electrode materials is vanadium pentoxide, which will be discussed in this review, due to its low cost and high theoretical capacity. Additionally, aqueous electrolytes, which are environmentally safe, provide an alternative approach compared to organic media for safe, cost-effective, and scalable energy storage. In this review, we will reveal the industrial potential of competitive methods to grow cathodes with excellent stability and enhanced electrochemical performance in aqueous media and lay the foundation for the large-scale production of electrode materials.


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