| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
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| 3. |
- Chen, Shiqian, et al.
(författare)
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Ultrafast metal-free microsupercapacitor arrays directly store instantaneous high-voltage electricity from mechanical energy harvesters
- 2024
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Ingår i: Advanced Science. - : Wiley. - 2198-3844. ; 11:22
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Tidskriftsartikel (refereegranskat)abstract
- Harvesting renewable mechanical energy is envisioned as a promising and sustainable way for power generation. Many recent mechanical energy harvesters are able to produce instantaneous (pulsed) electricity with a high peak voltage of over 100 V. However, directly storing such irregular high-voltage pulse electricity remains a great challenge. The use of extra power management components can boost storage efficiency but increase system complexity. Here utilizing the conducting polymer PEDOT:PSS, high-rate metal-free micro-supercapacitor (MSC) arrays are successfully fabricated for direct high-efficiency storage of high-voltage pulse electricity. Within an area of 2.4 × 3.4 cm2 on various paper substrates, large-scale MSC arrays (comprising up to 100 cells) can be printed to deliver a working voltage window of 160 V at an ultrahigh scan rate up to 30 V s−1. The ultrahigh rate capability enables the MSC arrays to quickly capture and efficiently store the high-voltage (≈150 V) pulse electricity produced by a droplet-based electricity generator at a high efficiency of 62%, significantly higher than that (<2%) of the batteries or capacitors demonstrated in the literature. Moreover, the compact and metal-free features make these MSC arrays excellent candidates for sustainable high-performance energy storage in self-charging power systems.
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| 4. |
- Chen, Zhen, et al.
(författare)
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Multifunctional conductive hydrogels and their applications as smart wearable devices
- 2021
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Ingår i: Journal of materials chemistry. B. - : Royal Society of Chemistry (RSC). - 2050-750X .- 2050-7518. ; 9:11, s. 2561-2583
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Forskningsöversikt (refereegranskat)abstract
- Recently, hydrogekbased conductive materials and their applications as smart wearable devices have been paid tremendous attention due to their high stretchability, flexibility, and excellent biocompatibility. Compared with single functional conductive hydrogels, multifunctional conductive hydrogels are more advantageous to match various demands for practical applications. This review focuses on multifunctional conductive hydrogels applied for smart wearable devices. Representative strategies for conduction of hydrogels are discussed firstly: (1) electronic conduction based on the conductive fillers and (2) ionic conduction based on charged ions. Then, the common and intensive research on multiple functionahties of conductive hydrogels, such as mechanical properties, conductive and sensory properties, anti-freezing and moisturizing properties, and adhesion and self-healing properties is presented. The applications of multifunctional conductive hydrogels such as in human motion sensors, sensory skins, and personal healthcare diagnosis are provided in the third part. Finally, we offer our perspective on open challenges and future areas of interest for multifunctional conductive hydrogels used as smart wearable devices.
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| 5. |
- Lou, Xiaolong, et al.
(författare)
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An Integrated Application of Motion Sensing and Eye Movement Tracking Techniques in Perceiving User Behaviors in a Large Display Interaction
- 2023
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Ingår i: Machines. - : MDPI AG. - 2075-1702. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- In public use of a large display, it is a usual phenomenon that multiple users individually participate in respective tasks on a common device. Previous studies have categorized such activity as independent interaction that involves little group engagement. However, by investigating how users approach, participate in, and interact with large displays, we found that parallel use is affected by group factors such as group size and between-user relationship. To gain a thorough understanding of individual and group behaviors, as well as parallel interaction task performance, one 70-inch display-based information searching task and experiment was conducted, in which a mobile eye movement tracking headset and a motion sensing RGB-depth sensor were simultaneously applied. The results showed that (1) a larger group size had a negative influence on the group users’ concentration on the task, perceived usability, and user experience; (2) a close relationship between users contributed to occasional collaborations, which was found to improve the users’ task completion time efficiency and their satisfaction on the large display user experience. This study proves that an integrated application of eye movement tracking and motion sensing is capable of understanding individual and group users’ behaviors simultaneously, and thus is a valid and reliable scheme in monitoring public activities that can be widely used in public large display systems.
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| 6. |
- Su, Yingchun, et al.
(författare)
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Monolithic Fabrication of Metal‐Free On‐Paper Self‐Charging Power Systems
- 2024
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028.
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Tidskriftsartikel (refereegranskat)abstract
- Self-charging power systems (SCPSs) are envisioned as promising solutions for emerging electronics to mitigate the increasing global concern about battery waste. However, present SCPSs suffer from large form factors, unscalable fabrication, and material complexity. Herein, a type of highly stable, eco-friendly conductive inks based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) are developed for direct ink writing of multiple components in the SCPSs, including electrodes for miniaturized spacer-free triboelectric nanogenerators (TENGs) and microsupercapacitors (MSCs), and interconnects. The principle of “one ink, multiple functions” enables to almost fully print the entire SCPSs on the same paper substrate in a monolithic manner without post-integration. The monolithic fabrication significantly improves the upscaling capability for manufacturing and reduces the form factor of the entire SCPSs (a small footprint area of ≈2 cm × 3 cm and thickness of ≈1 mm). After pressing/releasing the TENGs for ≈79000 cycles, the 3-cell series-connected MSC array can be charged to 1.6 V while the 6-cell array to 3.0 V. On-paper SCPSs are promising to serve as lightweight, thin, sustainable, and low-cost power supplies.
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| 7. |
- Su, Yingchun, et al.
(författare)
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Monolithic Fabrication of On-Paper Self-Charging Power Systems Through Direct Ink Writing
- 2024
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Ingår i: NordPac 2024 - 60th Annual Microelectronics and Packaging Conference and Exhibition. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- The rapid development of emerging electronics requires power sources with the advantages of lightweight, high efficiency, and portability. Considering the use of critical raw materials (such as Li, Co, etc.) and the increasing global concern of battery waste, self-charging power systems (SCPSs) integrating energy harvesting, power management, and energy storage devices have been envisioned as promising solutions to replace traditional batteries to avoid the use of toxic materials and the need of frequent recharging/replacement. Up to date, the reported SCPSs still hold the problem of large form factor, unscalable fabrication, noble materials, and material complexity. In our work, a highly stable and eco-friendly organic conductive ink based on poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) has been developed for monolithic fabrication on-paper SCPSs almost fully through a simple direct ink writing (DIW) process. The ink possesses multiple functions and enables to directly print almost all the key components in the SCPSs, including electrodes for triboelectric nanogenerators (TENGs, mechanical energy harvesters), electrodes for micro-supercapacitors (MSCs, energy storage devices), and interconnects, on the same paper substrate in a monolithic manner without the need for “post-integration”. The monolithic printing process exhibits excellent upscaling capability for manufacturing. In particular, the direct patterning merit of the DIW process offers great flexibility in optimizing the system performance through adjusting the cell number, electrode dimension, and thickness of the MSC arrays. By adjusting the cell numbers, the MSC arrays attain high-rate capability up to 50 V/s to match the pulsing electricity produced from the TENGs. For small-size printed SCPSs (~ 2 cm × 3 cm ×1 mm), after continuous press and release of the TENGs for ~79000 cycles, the 3-cell series-connected MSC array can be charged to 1.6 V while 6-cell array to 3.0 V. For a larger-size printed SCPS with 30 MSC cells (~ 7.5 cm × 5 cm ×0.5 mm), after charging through pressing/releasing for 10 min (nearly 1200 cycles), it can light up a LED (~ 4 W) for 5 s. The demo of successfully powering an LED device exhibited its great potential for powering various electronics. The monolithically fabricated on-paper SCPSs have great potential to serve as lightweight, thin, sustainable, eco-friendly, and low-cost power supplies for emerging electronics.
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