| 1. |
- Li, Qifan, et al.
(författare)
-
A Highly Conductive n-Type Conjugated Polymer Synthesized in Water
- 2024
-
Ingår i: Journal of the American Chemical Society. - : AMER CHEMICAL SOC. - 0002-7863 .- 1520-5126.
-
Tidskriftsartikel (refereegranskat)abstract
- Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a benchmark hole-transporting (p-type) polymer that finds applications in diverse electronic devices. Most of its success is due to its facile synthesis in water, exceptional processability from aqueous solutions, and outstanding electrical performance in ambient. Applications in fields like (opto-)electronics, bioelectronics, and energy harvesting/storage devices often necessitate the complementary use of both p-type and n-type (electron-transporting) materials. However, the availability of n-type materials amenable to water-based polymerization and processing remains limited. Herein, we present a novel synthesis method enabling direct polymerization in water, yielding a highly conductive, water-processable n-type conjugated polymer, namely, poly[(2,2 '-(2,5-dihydroxy-1,4-phenylene)diacetic acid)-stat-3,7-dihydrobenzo[1,2-b:4,5-b ']difuran-2,6-dione] (PDADF), with remarkable electrical conductivity as high as 66 S cm(-1), ranking among the highest for n-type polymers processed using green solvents. The new n-type polymer PDADF also exhibits outstanding stability, maintaining 90% of its initial conductivity after 146 days of storage in air. Our synthetic approach, along with the novel polymer it yields, promises significant advancements for the sustainable development of organic electronic materials and devices.
|
|
| 2. |
- Liu, Tiefeng, et al.
(författare)
-
Ground-state electron transfer in all-polymer donor:acceptor blends enables aqueous processing of water-insoluble conjugated polymers
- 2023
-
Ingår i: Nature Communications. - : NATURE PORTFOLIO. - 2041-1723. ; 14:1
-
Tidskriftsartikel (refereegranskat)abstract
- Water-based conductive inks are vital for the sustainable manufacturing and widespread adoption of organic electronic devices. Traditional methods to produce waterborne conductive polymers involve modifying their backbone with hydrophilic side chains or using surfactants to form and stabilize aqueous nanoparticle dispersions. However, these chemical approaches are not always feasible and can lead to poor material/device performance. Here, we demonstrate that ground-state electron transfer (GSET) between donor and acceptor polymers allows the processing of water-insoluble polymers from water. This approach enables macromolecular charge-transfer salts with 10,000x higher electrical conductivities than pristine polymers, low work function, and excellent thermal/solvent stability. These waterborne conductive films have technological implications for realizing high-performance organic solar cells, with efficiency and stability superior to conventional metal oxide electron transport layers, and organic electrochemical neurons with biorealistic firing frequency. Our findings demonstrate that GSET offers a promising avenue to develop water-based conductive inks for various applications in organic electronics. Chemical approaches to improve aqueous dispersions of conjugated polymers are limited by the feasibility of modifying the backbone or lead to poor performance. Here, Liu et al. show that ground-state electron transfer in donor:acceptor blends aids aqueous dispersion, for high conductivity and solubility.
|
|
| 3. |
- Chen, Silan, et al.
(författare)
-
Interaction relationship between urban domestic energy consumption and water use - a case study of Beijing and Shanghai
- 2016
-
Ingår i: Water Policy. - : IWA Publishing. - 1366-7017 .- 1996-9759. ; 18:3, s. 670-684
-
Tidskriftsartikel (refereegranskat)abstract
- Energy consumption and water use are inextricably linked. Combining research on energy consumption and water use in an urban context provides a scientific basis for the integrated planning of energy and water supply systems. Domestic energy and water are among the most consumed resources in urban environments. Furthermore, domestic resources represent an increasing proportion of the total resources consumed. This paper explores four key indicators of urban energy consumption (UEC) and water use in Beijing and Shanghai for the period of 2000 to 2011. Using correlation analysis, this study establishes the intrinsic relationship between UEC and water use. It also offers an analysis of the consumption trends of these two resources as well as their interactive relationship. The results show that urban domestic energy consumption (UDEC) and water use have a significant linear correlation: UDEC is positively correlated with water use, and the correlation coefficients of Beijing and Shanghai are 0.81 and 0.97, respectively. In Beijing, urban domestic energy and water use per capita are negatively correlated, with the high correlation coefficient of 0.93. In Shanghai, urban domestic energy and water use per capita are positively correlated, with the correlation coefficient of 0.90.
|
|
| 4. |
- Lu, Weifeng, et al.
(författare)
-
β cell function and insulin resistance have gender-specific correlations with carotid intima-media thickness in type 2 diabetes
-
Ingår i: International Journal of Diabetes in Developing Countries. - 0973-3930.
-
Tidskriftsartikel (refereegranskat)abstract
- ObjectiveThe relationships between carotid intima-media thickness (C-IMT) and β cell function and insulin resistance in patients with type 2 diabetes (T2D) have not been fully elucidated. This study is to investigate whether impaired glucose metabolism is etiologically associated with C-IMT in patients with T2D.MethodsThe study group consisted of 490 (284 men, 206 women) participants. Venous blood specimens were obtained from all subjects for biochemical profiles after an >8-h overnight fast. C-IMT was measured as the distance between the luminal-intimal leading edge (I-line) and the medial-adventitial leading edge (M-line) on the far wall. Insulin resistance was estimated with the homeostasis model assessment of insulin resistance (HOMA-IR). The acute insulin response to arginine was calculated as the mean of the three plasma insulin levels obtained within 2, 4, and 6 min after the arginine bolus minus the pre-stimulus plasma insulin levels.ResultsThere was a graded increase in C-IMT values according to tertiles of HOMA-IR in men; the values of C-IMT were significantly decreased across the tertiles of acute insulin and C-peptide responses in women. Multivariate analysis revealed that HOMA-IR and age were positively associated with C-IMT among men participants, and acute insulin response and current smoking were the independent determinants of C-IMT in women.ConclusionEarly insulin response stimulated by arginine is independently associated with C-IMT in women T2D individuals, whereas insulin resistance is positively correlated with C-IMT in men T2D subjects.
|
|
| 5. |
- Massetti, Matteo, et al.
(författare)
-
Fully 3D-printed organic electrochemical transistors
- 2023
-
Ingår i: NPJ FLEXIBLE ELECTRONICS. - : NATURE PORTFOLIO. - 2397-4621. ; 7:1
-
Tidskriftsartikel (refereegranskat)abstract
- Organic electrochemical transistors (OECTs) are being researched for various applications, ranging from sensors to logic gates and neuromorphic hardware. To meet the requirements of these diverse applications, the device fabrication process must be compatible with flexible and scalable digital techniques. Here, we report a direct-write additive process to fabricate fully 3D-printed OECTs, using 3D printable conducting, semiconducting, insulating, and electrolyte inks. These 3D-printed OECTs, which operate in the depletion mode, can be fabricated on flexible substrates, resulting in high mechanical and environmental stability. The 3D-printed OECTs have good dopamine biosensing capabilities (limit of detection down to 6 mu M without metal gate electrodes) and show long-term (similar to 1 h) synapse response, indicating their potential for various applications such as sensors and neuromorphic hardware. This manufacturing strategy is suitable for applications that require rapid design changes and digitally enabled direct-write techniques.
|
|
| 6. |
- Padinhare, Harikesh, et al.
(författare)
-
Ion-tunable antiambipolarity in mixed ion-electron conducting polymers enables biorealistic organic electrochemical neurons
- 2023
-
Ingår i: Nature Materials. - : NATURE PORTFOLIO. - 1476-1122 .- 1476-4660. ; 22, s. 242-248
-
Tidskriftsartikel (refereegranskat)abstract
- Biointegrated neuromorphic hardware holds promise for new protocols to record/regulate signalling in biological systems. Making such artificial neural circuits successful requires minimal device/circuit complexity and ion-based operating mechanisms akin to those found in biology. Artificial spiking neurons, based on silicon-based complementary metal-oxide semiconductors or negative differential resistance device circuits, can emulate several neural features but are complicated to fabricate, not biocompatible and lack ion-/chemical-based modulation features. Here we report a biorealistic conductance-based organic electrochemical neuron (c-OECN) using a mixed ion-electron conducting ladder-type polymer with stable ion-tunable antiambipolarity. The latter is used to emulate the activation/inactivation of sodium channels and delayed activation of potassium channels of biological neurons. These c-OECNs can spike at bioplausible frequencies nearing 100 Hz, emulate most critical biological neural features, demonstrate stochastic spiking and enable neurotransmitter-/amino acid-/ion-based spiking modulation, which is then used to stimulate biological nerves in vivo. These combined features are impossible to achieve using previous technologies.
|
|
| 7. |
- Zhang, Silan, 1992-
(författare)
-
Organic Electrochemical Transistors : Materials and Challenges
- 2023
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The use of organic mixed ionic-electronic conductors (OMIECs) has demonstrated the potential to transform the field of bioelectronics, spanning from medical diagnostics to neuromorphic computing hardware. To keep up with the fast-paced demands, it is crucial to develop customizable device fabrication, design new materials, improve operation stability, and explore the ion-electron interactions within OMIECs. This thesis explores the application of OMIECs in organic electrochemical transistors (OECTs), a crucial component of a range of organic bioelectronic devices. To meet applications requiring rapid design iterations and leveraging digitally enabled direct-write techniques, we developed a novel approach for fabricating fully 3D-printed OECTs using a direct-write additive process. This method involves utilizing 3D printable inks with conductive, semiconductive, insulating, and electrolyte properties. The resulting fully 3D-printed OECTs operate in the depletion mode and can be produced on flexible substrates, ensuring excellent mechanical durability and resilience in various environmental conditions. These 3D-printed OECTs exhibit impressive dopamine biosensing capabilities, detecting concentrations as low as 6 µM without the need for metal gate electrodes. Furthermore, they demonstrate long-term memory response lasting up to approximately 1 hour, highlighting their potential for diverse applications such as sensors and neuromorphic hardware. We have addressed the issue of sluggish response times in printed OECTs by utilizing multi-walled carbon nanotubes (MWCNTs) and the π-conjugated redox polymer called poly(benzimidazobenzo-phenanthroline) (BBL) to create high-performing n-type OECTs. By incorporating MWCNTs, we were able to improve the electron mobility of the transistors by more than 10 times, resulting in a rapid response time of just 15 ms and a high μC* value (which is the product of electron mobility and volumetric capacitance) of approximately 1 F cm–1 V−1 s−1. These breakthroughs have allowed us to develop complementary inverters that have a voltage gain of over 16, a significant worst-case noise margin at a supply voltage lower than 0.6 V and consume less than 1 µW of power. However, the operational stability of complementary inverters is hindered by the degradation of p-type OMIECs. The oxygen reduction reaction (ORR) is a common electrochemical side reaction that poses challenges to the stability of OECTs, but the underlying connection between ORR and material degradation remains poorly understood. In our investigation, we examined the influence of ORR on the stability and degradation mechanisms of thiophene-based OECTs. Our findings reveal that the polymer backbone experiences degradation as a result of the pH increase during ORR. To address this issue, we introduced a protective polymer glue layer between the semiconductor channel and the aqueous electrolyte, effectively suppressing the occurrence of ORR and significantly enhancing the stability of the OECTs. This improvement is evident in the nearly 90% retention of current during ≈2 hours of cycling in the saturation regime. Finally, we investigated the ionic-electronic transport properties in BBL-based OECTs using various electrolytes. We found that the peak drain current is achieved at a doping level of 1 electron per repeating unit, decreasing thereafter. The interaction between ions and the polymer reduces the voltage needed for this level of doping but also lowers the peak drain current. Unlike thiophene-based OECTs, larger cation sizes don't improve BBL-based OECT performance. Additionally, Lewis acids adversely affect BBL's electrical properties due to their impact on the polymer microstructure. We hope these studies will inspire our peers in the field of materials synthesis, device processing, and scalable digital techniques, paving the way for next-generation, reliable, and safe bioelectronics.
|
|
| 8. |
- Zhang, Silan, et al.
(författare)
-
Synergistic Effect of Multi-Walled Carbon Nanotubes and Ladder-Type Conjugated Polymers on the Performance of N-Type Organic Electrochemical Transistors
- 2022
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-3028 .- 1616-301X. ; 32:1
-
Tidskriftsartikel (refereegranskat)abstract
- Organic electrochemical transistors (OECTs) have the potential to revolutionize the field of organic bioelectronics. To date, most of the reported OECTs include p-type (semi-)conducting polymers as the channel material, while n-type OECTs are yet at an early stage of development, with the best performing electron-transporting materials still suffering from low transconductance, low electron mobility, and slow response time. Here, the high electrical conductivity of multi-walled carbon nanotubes (MWCNTs) and the large volumetric capacitance of the ladder-type π-conjugated redox polymer poly(benzimidazobenzophenanthroline) (BBL) are leveraged to develop n-type OECTs with record-high performance. It is demonstrated that the use of MWCNTs enhances the electron mobility by more than one order of magnitude, yielding fast transistor transient response (down to 15 ms) and high μC* (electron mobility × volumetric capacitance) of about 1 F cm−1 V−1 s−1. This enables the development of complementary inverters with a voltage gain of >16 and a large worst-case noise margin at a supply voltage of <0.6 V, while consuming less than 1 µW of power.
|
|
| 9. |
- Zhang, Silan, et al.
(författare)
-
Toward Stable p-Type Thiophene-Based Organic Electrochemical Transistors
- 2023
-
Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 33:40
-
Tidskriftsartikel (refereegranskat)abstract
- Operational stability is essential for the success of organic electrochemical transistors (OECTs) in bioelectronics. The oxygen reduction reaction (ORR) is a common electrochemical side reaction that can compromise the stability of OECTs, but the relationship between ORR and materials degradation is poorly understood. In this study, the impact of ORR on the stability and degradation mechanisms of thiophene-based OECTs is investigated. The findings show that an increase in pH during ORR leads to the degradation of the polymer backbone. By using a protective polymer glue layer between the semiconductor channel and the aqueous electrolyte, ORR is effectively suppressed and the stability of the OECTs is significantly improved, resulting in current retention of nearly 90% for & AP;2 h cycling in the saturation regime.
|
|
