scholarly journals Upcycling Compact Discs for Bioelectronic Applications

Author(s):  
Matthew Brown ◽  
Louis Somma ◽  
Melissa Mendoza ◽  
Yeonsik Noh ◽  
Gretchen Mahler ◽  
...  

Abstract Electronic waste (e-waste) is a global issue brought about by the short lifespan of electronics. Viable methods to relieve the inundated disposal system by repurposing the enormous amount of e-waste remain elusive. Inspired by the need for sustainable solutions, this study resulted in a multifaceted approach to upcycling compact discs (CDs). The once-ubiquitous plates can be transformed into stretchable and flexible biosensors. Our experiments and advanced prototypes show that effective, innovative biosensors can be developed at a low-cost. An affordable craft-based mechanical cutter allows pre-determined patterns to be scored on the recycled metal, an essential first step for producing stretchable, wearable electronics. The active metal harvested from the CDs was inert, cytocompatible, and capable of vital biopotential measurements. Additional studies examined the material’s resistive emittance, temperature sensing, real-time metabolite monitoring performance, and moisture-triggered transience. This sustainable approach for upcycling e-waste provides an advantageous research-based waste stream that does not require cutting-edge microfabrication facilities, expensive materials, and high-caliber engineering skills.

Landslides ◽  
2021 ◽  
Author(s):  
Lorenzo Brezzi ◽  
Alberto Bisson ◽  
Davide Pasa ◽  
Simonetta Cola

AbstractA large number of landslides occur in North-Eastern Italy during every rainy period due to the particular hydrogeological conditions of this area. Even if there are no casualties, the economic losses are often significant, and municipalities frequently do not have sufficient financial resources to repair the damage and stabilize all the unstable slopes. In this regard, the research for more economically sustainable solutions is a crucial challenge. Floating composite anchors are an innovative and low-cost technique set up for slope stabilization: it consists in the use of passive sub-horizontal reinforcements, obtained by coupling a traditional self-drilling bar with some tendons cemented inside it. This work concerns the application of this technique according to the observational method described within the Italian and European technical codes and mainly recommended for the design of geotechnical works, especially when performed in highly uncertain site conditions. The observational method prescribes designing an intervention and, at the same time, using a monitoring system in order to correct and adapt the project during realization of the works on the basis of new data acquired while on site. The case study is the landslide of Cischele, a medium landslide which occurred in 2010 after an exceptional heavy rainy period. In 2015, some floating composite anchors were installed to slow down the movement, even if, due to a limited budget, they were not enough to ensure the complete stabilization of the slope. Thanks to a monitoring system installed in the meantime, it is now possible to have a comparison between the site conditions before and after the intervention. This allows the evaluation of benefits achieved with the reinforcements and, at the same time, the assessment of additional improvements. Two stabilization scenarios are studied through an FE model: the first includes the stabilization system built in 2015, while the second evaluates a new solution proposed to further increase the slope stability.


2021 ◽  
Author(s):  
Faisal Haq Shaheen

Pakistan’s urban informal sector (IS) has been the subject of increased attention in recent years. In light of national policy failures and the rapid growth of the IS, this study asks whether there are differences in the political will and capacity in engaging the IS between upper and lower tiered state actors, and whether this engagement can be in a sustainable manner. The social contexts of housing, water and sanitation, transportation and labor conditions are examined in the cities of Lahore and Karachi to assess the experiences of the urban informal sector’s engagement with the state. A survey of state and non-state actors is carried out in field interviews to obtain the perspectives of state policies towards the IS as well as to understand the processes, constraints and possible solutions to engaging the IS. Evidence from the study supports the hypothesis that lower tiers of the state are capable of engaging the IS, but due to constraints from upper levels, are unable to do so. The study’s findings suggest that the combination of grassroots civil society efforts in mobilizing the urban IS alongside the provision of well resourced, accountable capacities of lower tiers of municipal government can generate low cost sustainable solutions to urban service delivery. Evidence also points to the benefits of civil society’s engagement with lower tiers of government to ensure that upper-level bureaucrats are held accountable for ill-conceived policy and its failures. The research shows that before success in national and provincial policy reforms can be expected, emphasis of policy has to be on the recognition and development of interactions between the IS and lower tiers of the state.


2019 ◽  
Vol 16 (3) ◽  
pp. 117-123
Author(s):  
Tsung-Ching Huang ◽  
Ting Lei ◽  
Leilai Shao ◽  
Sridhar Sivapurapu ◽  
Madhavan Swaminathan ◽  
...  

Abstract High-performance low-cost flexible hybrid electronics (FHE) are desirable for applications such as internet of things and wearable electronics. Carbon nanotube (CNT) thin-film transistor (TFT) is a promising candidate for high-performance FHE because of its high carrier mobility, superior mechanical flexibility, and material compatibility with low-cost printing and solution processes. Flexible sensors and peripheral CNT-TFT circuits, such as decoders, drivers, and sense amplifiers, can be printed and hybrid-integrated with thinned (<50 μm) silicon chips on soft, thin, and flexible substrates for a wide range of applications, from flexible displays to wearable medical devices. Here, we report (1) a process design kit (PDK) to enable FHE design automation for large-scale FHE circuits and (2) solution process-proven intellectual property blocks for TFT circuits design, including Pseudo-Complementary Metal-Oxide-Semiconductor (Pseudo-CMOS) flexible digital logic and analog amplifiers. The FHE-PDK is fully compatible with popular silicon design tools for design and simulation of hybrid-integrated flexible circuits.


Author(s):  
Jiang Zhao ◽  
Jiahao Gui ◽  
Jinsong Luo ◽  
Jing Gao ◽  
Caidong Zheng ◽  
...  

Abstract Graphene-based pressure sensors have received extensive attention in wearable devices. However, reliable, low-cost, and large-scale preparation of structurally stable graphene electrodes for flexible pressure sensors is still a challenge. Herein, for the first time, laser-induced graphene (LIG) powder are prepared into screen printing ink, and shape-controllable LIG patterned electrodes can be obtained on various substrates using a facile screen printing process, and a novel asymmetric pressure sensor composed of the resulting screen-printed LIG electrodes has been developed. Benefit from the 3D porous structure of LIG, the as-prepared flexible LIG screen-printed asymmetric pressure sensor has super sensing properties with a high sensitivity of 1.86 kPa−1, low detection limit of about 3.4 Pa, short response time, and long cycle durability. Such excellent sensing performances give our flexible asymmetric LIG screen-printed pressure sensor the ability to realize real-time detection of tiny body physiological movements (such as wrist pulse and pronunciation action). Besides, the integrated sensor array has a multi-touch function. This work could stimulate an appropriate approach to designing shape-controllable LIG screen-printed patterned electrodes on various flexible substrates to adapt the specific needs of fulfilling compatibility and modular integration for potential application prospects in wearable electronics.


Author(s):  
Sanjay Kumar Koli ◽  
Athar Hussain

Electronics waste is becoming a major global issue. Huge accumulation of e-waste and its recycling through primitive means for extraction of precious metals are a real concern in the developing countries due to the presence of hazardous materials in e-waste. The major portion of e-waste generated domestically as well as illegally imported is recycled in a crude manner leading to pollution of the environment. Current practices of e-waste management in India encounters many challenges like the difficulty in inventorization, ineffective regulations, pathetic and unsafe conditions of informal recycling, poor awareness of consumers, and reluctance on part of stakeholders to address the issues. As a result, toxic materials enter waste stream with no special precautions to avoid the known adverse impacts on the environment and human health. Resources are wasted when economically valuable materials are dumped. This chapter highlights the hazards caused due to improper handling of e-wastes and also describes some appropriate measures to be adopted for its management and safe disposal.


2020 ◽  
pp. 152808372091441
Author(s):  
Gizem Kayabaşı ◽  
Özgü Özen ◽  
Demet Yılmaz

Electronic or conductive textiles have attracted particular attention because of their potential applications in the fields of energy storage, supercapacitors, solar cells, health care devices, etc. Contrary to solid materials, the properties of textile materials such as stretchability, foldability, washability, etc. make the textiles ideal support materials for electronic devices. Therefore, in recent years, various conductive materials and production methods have been researched extensively to make the textiles conductive. In the present study, an alternative method based on imparting the conductivity to the fiber-based structure for the production of conductive textiles was established. Considering the contribution of unique characteristics of the fiber-based structure to the clothing systems, imparting the conductivity to the fibrous structure before yarn and fabric production may help to protect the breathable, lightweight, softness, deformable and washable of textile structure, and hence to improve the wearability properties of the electronic textiles. In the study, carbon black nanoparticles were selected as a conductive material due to low cost and easy procurable while cotton fiber together with other fiber types such as polyester, acrylic and viscose rayon fibers were used due to their common usage in the textile industry. In addition, various production parameters (CB concentration, feeding rate, etc.) were analyzed and the results indicated that the developed alternative method is capable to produce conductive yarns and electrical resistance of the yarns was about 94–4481 kΩ. The yarns had comparable yarn tenacity and breaking elongation properties, and still carried conductive character even after washing. In literature, there has been no effort to get conductivity in this manner and the method can be considered to be a new application for added-on or built-in future wearable electronics. Also, in the study, produced conductive yarns were used as a collector to gather the nanofibers onto the yarn to produce hybrid yarns enabling the production of functional textile products.


2003 ◽  
Vol 769 ◽  
Author(s):  
YongWoo Choi ◽  
Ioannis Kymissis ◽  
Annie Wang ◽  
Akintunde I. Akinwande

AbstractTextiles are a suitable substrate for large area, flexible and wearable electronics because of their excellent flexibility, mechanical properties and low cost manufacturability. The ability to fabricate active devices on fiber is a key step for achieving large area and flexible electronic structures. We fabricated transistors and inverters with a-Si film and pentacene film on Kapton film and cut them into fibers. The a-Si TFT showed a threshold voltage of 8.5 V and on/off ratio of 103 at a drain voltage of 10 V. These are similar to the characteristics of a TFT fabricated on a glass substrate at the same time. The maximum gain of the inverter with an enhancement n-type load was 6.45 at a drain voltage of 10 V. The pentacene OTFT showed a threshold voltage of -8 V and on/off ratio of 103 at a drain voltage of -30 V. The inverter with a depletion p-type load showed a voltage inversion but the inversion occurred at the wrong voltage. The antifuse was successfully programmed with a voltage pulse and also a current pulse. The resistance decreased from 10 GΩ to 2 kΩ after the programming.


2019 ◽  
Vol 133 (11) ◽  
pp. 930-935 ◽  
Author(s):  
Declan C Murphy

AbstractBackgroundENT disease prevalence, risk factors and treatment vary between developed and developing countries. Health provision, particularly disease prevention strategies and surgery, in developing countries is poor, manifesting as a high frequency of common and preventable diseases. Healthcare systems in developing countries are unsustainable, and the technological advances that provide ENT surgery with novel diagnostic and treatment opportunities are inaccessible.ConclusionA multifaceted approach is essential to improve the care of patients with ENT diseases in developing countries. Public health efforts must focus on educating the local community, reducing high-risk behaviours and decreasing the frequency of preventable diseases. Governments must be pressured to prioritise the funding of long-term, sustainable efforts with effective disease prevention strategies. Providing local healthcare professionals with high-quality ENT training so that self-sustaining and low-cost care can be delivered, mainly in a primary care setting, is key.


2016 ◽  
Vol 4 (6) ◽  
pp. 2096-2104 ◽  
Author(s):  
Fei Li ◽  
Hao Chen ◽  
Xiao Ying Liu ◽  
Shi Jin Zhu ◽  
Jia Qi Jia ◽  
...  

The development of portable and wearable electronics has promoted the increasing demand for high-performance power sources with high energy/power density, low cost, lightweight, as well as ultrathin and flexible features.


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