High‐Performance Pressure Sensors Based on Shaped Gel Droplet Arrays

Polymer gel-based pressure sensors offer numerous advantages over traditional sensing technologies, including excellent conformability and integration into wearable devices. However, challenges persist in terms of their performance and manufacturing technology. In this study, a method for fabricating gel pressure sensors using a hydrophobic/hydrophilic patterned surface is introduced. By shaping and fine-tuning the droplets of the polymer gel prepolymerization solution on the patterned surface, remarkable sensitivity improvements compared to unshaped hydrogels have been achieved. This also showcased the potential for tailoring gel pressure sensors to different applications. By optimizing the configuration of the sensor array, an uneven conductive gel array is fabricated, which exhibited a high sensitivity of 0.29 kPa$^{−1}$ in the pressure range of 0–30 kPa, while maintaining a sensitivity of 0.13 kPa$^{−1}$ from 30 kPa up to 100 kPa. Furthermore, the feasibility of using these sensors for human motion monitoring is explored and a conductive gel array for 2D force detection is successfully developed. This efficient and scalable fabrication method holds promise for advancing pressure sensor technology and offers exciting prospects for various industries and research fields

Enhancing Temperature Responsiveness of PNIPAM Through 3D‐Printed Hierarchical Porosity

Materials with ultra-fast responsive properties are essential for variousapplications. Among the responsive materials, poly(N-isopropylacrylamide)(PNIPAM) stands out due to its well-studied temperature-responsiveproperties. Improving the kinetics of the responsive properties of PNIPAMis, however, still essential for advancing its practical use. Here, the responsiverate of PNIPAM hydrogels is enhanced by first incorporating sub-micrometerporosity into the material through polymerization-induced phase separation(PIPS), followed by introducing millimeter scale pores via 3D printing, therebyrendering the material with hierarchical porosity. The 3D-printed porousPNIPAM structures show accelerated swelling and deswelling, when comparedto non-porous PNIPAM structures, due to enhanced water permeability asso-ciated with the continuous network of micrometer to millimeter-sized pores.Additionally, thinner polymer structures result in faster temperature responserates. At the same time, the mechanical strength of PNIPAM hydrogels withhigh porosity and thinner polymer walls is not compromised, overcomingthe common trade-off between swelling and mechanical properties

Exceptional capture of methane at low pressure by an iron‐based metal‐organic framework

The selective capture of methane (CH4) at low concentrations and its separation from N2 are extremely challenging owing to the weak host-guest interactions between CH4 molecules and any sorbent material. Here, we report the exceptional adsorption of CH4 at low pressure and efficient separation of CH4/N2 by MFM-300(Fe). MFM-300(Fe) shows a very high uptake for CH4 of 0.85 mmol g−1 at 1 mbar and 298 K and a record CH4/N2 selectivity of 45 for porous solids, representing a new benchmark for CH4 capture and CH4/N2 separation. The excellent separation of CH4/N2 by MFM-300(Fe) has been confirmed by dynamic breakthrough experiments. In situ neutron powder diffraction, and solid-state nuclear magnetic resonance and diffuse reflectance infrared Fourier transform spectroscopies, coupled with modelling, reveal a unique and strong binding of CH4 molecules involving Fe-OH···CH4 and C···phenyl ring interactions within the pores of MFM-300(Fe), thus promoting the exceptional adsorption of CH4 at low pressure

Comparison of small-strain shear modulus and Young’s modulus of dry sand measured by resonant column and bender–extender element

The small-strain shear modulus and Young’s modulus of dry sand are simultaneously measured by resonant column and bender–extender element tests. Two different methods are adopted to calibrate the resonant column and the results indicate that the conventional calibration method may significantly underestimate the Young’s modulus obtained in flexural excitation, while it only slightly underestimates the shear modulus obtained in torsional excitation. A new calibration method that establishes a calibration curve based on the resonant frequency is used to overcome the error. With this new calibration method, the shear modulus and Young’s modulus from the resonant column agree well with those from the bender–extender element. It convincingly explains the reason why a very small Poisson’s ratio was observed in previous resonant column tests and suggests that the effect of resonant frequency on the calibration results must be considered in flexural excitation.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Endoscopic thyroidectomy via chest-collarbone approach versus conventional open thyroidectomy: a retrospective comparative study

Objective(s): Endoscopic thyroidectomy, such as axillary, areola and transoral approaches, offer the advantage of a good cosmetic outcome, but it requires a wider dissection field compared to open thyroidectomy. Recently, chest-collarbone approach thyroidectomy has been widely developed in China because of its shorter anatomical route compared to other endoscopic approaches. This study retrospectively evaluated endoscopic thyroidectomy via chest-collarbone approach in patients with thyroid nodules to determine its feasibility. Methods: A total of 46 patients with thyroid disease who underwent endoscopic thyroidectomy between January 2022 and December 2022 were enrolled in the study and randomly matched to patients with thyroid disease who underwent open thyroidectomy at the same time based on nodule size and pathology. Postoperative bleeding, hoarseness situation, hospital stay, postoperative drainage volume, laryngeal nerve palsy, hypoparathyroidism and wound infection were assessed in both groups. Results: Forty-four patients underwent endoscopic thyroidectomy successfully and two patients changed to open thyroidectomy. The amount of postoperative drainage for the endoscopic thyroidectomy group was 102.78 ± 28.04 mL, and which was 71.91 ± 19.20 for open thyroidectomy group (p < 0.001). The postoperative hospital stay for the endoscopic thyroidectomy group was 8.78 ± 2.57 days, and which was 7.22 ± 1.13 for open thyroidectomy group (p < 0.001). There was no significant difference in postoperative bleeding, hoarseness situation, and wound infection between the two groups. Laryngeal nerve palsy, supraclavicular nerve injury and hypoparathyroidism were not observed in any patient during this study. Conclusion: Chest-collarbone endoscopic thyroid surgery is acceptable. This treatment improves in a good cosmetic outcome in patients with thyroid disease. To assess patients with preoperative nodule size and nature of the case is the impact of the success rate, which is particularly important

A Flexible Phosphonate Metal Organic Framework for Enhanced Cooperative Ammonia Capture

Ammonia (NH3) production in 2023 reached 150,000 million tons and is associated with concomitant production of 500 million tons of CO2 each year. Efforts to produce greenNH3 are compromised since it is difficult to separate using conventional condensation chillers, but in situ separation with minimal cooling is challenging. While metal-organic framework (MOF) materials offer some potential, they are often unstable and decompose in the presence of caustic and corrosive NH3. Here, we address these challenges by developing a pore-expansion strategy utilising the flexible phosphonate framework, STA-12(Ni), which shows exceptional stability and capture of NH3 at ppm levels at elevated temperatures (100 - 220°C) even under humid conditions. A remarkable NH3 uptake of 4.76 mmol g–1 at 100 microbar (equivalent to 100 ppm) is observed, and in situ neutron powder diffraction, inelastic neutron scattering, and infrared microspectroscopy, coupled with modelling, reveal a pore expansion from triclinic to rhombohedral structures on cooperative binding of NH3 to unsaturated Ni(II) sites and phosphonate groups. STA-12(Ni) can be readily engineered into pellets or monoliths without losing adsorption capacity, underscoring its practical potential