Pressure‐Temperature Dual‐Parameter Flexible Sensors Based on Conformal Printing of Conducting Polymer PEDOT:PSS on Microstructured Substrate

Abstract Flexible sensors play an important role in collecting stimuli information and sending them to a central processing unit or cloud for analysis and decision‐making. As much information is needed to be collected, the fabrication of multiparameter flexible sensors is becoming increasingly urgent. To this end, conducting polymer‐based composites have been proven as promising materials for developing pressure‐temperature dual‐parameter sensors. However, fabrication of ideal dual‐parameter sensors with fully decoupled pressure‐temperature readings, good sensitivity, and a simple preparation process remain challenges. Here, a strategy of fabricating a pressure‐temperature dual‐parameter sensor based on conformal printing of conducting polymer poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) on the surface of microstructured polydimethylsiloxane (PDMS) substrate is demonstrated. It is found that secondary doped PEDOT:PSS provides temperature‐independent conductivity. Combined with the sea‐island microstructured PDMS substrate, a screen‐printed flexible sensor demonstrates fully decoupled pressure‐temperature reading ability, competitive sensitivity, and good stability. The excellent sensing properties of the devices, with a maximum pressure sensitivity of 134.25 kPa−1 and linear response region over 300 kPa as well as highly sensitive temperature sensing for finger touch, together with their unique advantages of low‐cost and large‐area fabrication, make the printed flexible dual‐parameter sensors promising applications in electric‐skin (e‐skin), human‐machine interaction, and robotics

Erratum to “Pickering emulsions stabilized by whey protein nanoparticles prepared by thermal cross-linking”

The publisher regrets that minor errors occurred in the above paper. The errors relate to the Fig. 1C. Below is the correct Fig. 1C.</p

Pickering emulsions stabilized by whey protein nanoparticles prepared by thermal cross-linking

A Pickering (o/w) emulsion was formed and stabilized by whey protein isolate nanoparticles (WPI NPs). Those WPI NPs were prepared by thermal cross-linking of denatured WPI proteins within w/o emulsion droplets at 80. °C for 15. min. During heating of w/o emulsions containing 10% (w/v) WPI proteins in the water phase, the emulsions displayed turbid-transparent-turbid phase transitions, which is ascribed to the change in the size of the protein-containing water droplets caused by thermal cross-linking between denatured protein molecules. The transparent stage indicated the formation of WPI NPs. WPI NPs of different sizes were obtained by varying the mixing speed. WPI NPs of 200-500. nm were selected to prepare o/w Pickering emulsions because of their good stability against coalescence. By Confocal Laser Scanning Microscopy, it was observed that WPI NPs were closely packed and distributed at the surface of the emulsion droplets. By measuring water contact angles of WPI NPs films, it was found that under most conditions WPI NPs present good partial wetting properties, but that at the isoelectric point (p. I) and high ionic strength the particles become more hydrophobic, resulting in less stable Pickering emulsion. Thus, at pH above and below the p. I of WPI NPs and low to moderate ionic strengths (1-10. mM), and with a WPI NPs concentration of 2% (w/v), a stable Pickering emulsion can be obtained. The results may provide useful information for applications of WPI NPs in environmentally friendly and food grade applications, notably in food, pharmaceutical and cosmetic products

Design and Experiment of the Combined Machine for Transplanting Outcrop of Codonopsis with Micro Ridge Covered with Film

In response to the problem of no supporting equipment for the cultivation of Codonopsis in the hilly and mountainous areas of northwest China, a combined machine for transplanting outcrop of Codonopsis with micro ridges covered with film is designed. The key components of the prototype are analyzed and designed, and the structures and working parameters of the seedbed preparation device, seedling-casting device, rotary tillage soil-covering device, film-covering device, seedling head burial, and film edge soil-covering device are determined. The transmission system scheme is established, and the working mechanism of the core components is analyzed. Field experiments show that when the target seedling spacing is 4.4 cm and the machine moves forward at a speed of 0.1, 0.15, and 0.2 m/s, the variation coefficient of planting spacing and the qualification rate of planting depth meet the standard requirements. The qualified rate of planting posture and film side outcrop are greatly affected by the operating speed of the machine and decrease with the increase in operating speed. When the operating speed reaches 0.1 m/s, the average variation coefficient of planting spacing is 0.08% and the average qualified rate of planting depth, planting posture and film side outcrop is 95.83%, 94.17%, and 93.33%, respectively, which shows that the operating performance is better than that of the operating speeds of 0.15 m/s and 0.2 m/s. This study provides a new reference for the theoretical research and design of mechanized and automated transplanting machinery for Codonopsis seedlings

Formation and Characterization of Light-Responsive TEMPO-Oxidized Konjac Glucomannan Microspheres

A light-responsive delivery system has been developed. It consists of gelly micro­spheres made of TEMPO-oxidized Konjac gluco­mannan (OKGM) polymers where the carboxyl (COO^–) groups are cross-linked via ferric ions (Fe³⁺) and in which functional ingredients may be incorporated. By irradiation with (simulated) sunlight, the microspheres degrade, thereby releasing the encapsulated component(s). The degree of oxidation (DO) of the OKGM polymers could be well-controlled between 15 and 80%, as confirmed by proton titrations and FT-IR spectroscopy. OKGM of DO 80% was selected to prepare the microspheres because the high COO^– content leads to a high density of cross-links, yielding a strong gel. The electro­kinetic potential of the OKGM particles increases with increasing pH and decreasing salt concentration. Mössbauer and FT-IR spectroscopy revealed that the cross-links are formed through two modes of COO^––Fe³⁺ coordination, that is, 68.4% by bridging and 31.6% by unidentate binding. Thus, the unique properties of the OKGM microspheres make them potentially applicable as light-controlled biocompatible delivery systems