Laser-assisted micropyramid patterned PDMS encapsulation of 1D tellurium nanowires on cellulose paper for highly sensitive strain sensor and its photodetection studies.

This work demonstrates the fabrication of tellurium-nanowires (Te-NWs)/paper based device encapsulated using laser assisted mircopyramid patterned polydimethylsiloxane (PDMS) films. Although there are multiple reports published on 1D Te, most of them are limited to establishing its properties and studying its behavior as a sensor and research on the utilization of Te-NWs for physical sensors remain unexplored. Further, reports on p-type photodetectors also remain scarce. The fabricated Te-NWs/paper with micropyramid structured PDMS films encapsulation was used as a strain sensor, and it exhibited considerable improvement (∼60%) in sensitivity compared to smooth PDMS films. The gauge factor of the developed strain sensor was found to be âˆ¼15.3. In addition, fabricated Te-NWs/paper device with contacts was used as a photodetector and it showed photoresponsivity of âˆ¼22.5 mA W-1and âˆ¼14.5 mA W-1in visible and NIR regions, respectively. Furthermore, the device exhibited long-term mechanical stability under harsh deformations. Fabricated 1D Te-NWs/paper device was utilized as a strain sensor to monitor the angular movements in the human body and successfully monitored various human motions, including wrist bending, finger knuckle, elbow joint, and knee joint. The successful demonstration of Te-NWs based physical sensors and utilization in broadband photodetectors opens avenues of research for tellurium based flexible and wearable devices.

A mechanistic review on the dissolution phase behavior and supersaturation stabilization of amorphous solid dispersions.

Amorphous solid dispersion (ASD) technology is an attractive formulation approach for poorly soluble drugs because of the supersaturated state acquired during its dissolution. The high thermodynamic activity of the supersaturated state of the drug is also a driver for the enhanced absorptive flux across a membrane. However, this advantage can easily be lost due to the inherent instability of supersaturation, causing drug precipitation. Stabilizing the supersaturated state during the dissolution of ASD for the relevant absorption time frame is a challenging area in formulation research. Stabilizing the supersaturated state by using polymeric excipients and understanding the phase behavior of drugs during dissolution are required for the optimal performance of ASD formulations. A number of confounding kinetic, formulation and physiological factors can influence the evolution of supersaturation and phase changes during dissolution of ASDs. The review highlights the complex nature of dissolution of ASDs and the need of biorelevant dissolution for proper risk assessment and optimizing formulation development.

MOF based flexible, low-cost chemiresistive device as a respiration sensor for sleep apnea diagnosis.

The monitoring of respiratory disorders requires breath sensors that are fast, robust, and convenient to use and can function under real time conditions. A MOF based flexible sensor is reported for the first time for breath sensing applications. The properties of a highly porous HKUST-1 MOF and a conducting MoS2 material have been combined to fabricate an electronic sensor on a flexible paper support for studying sleep apnea problems. Extensive breath sensing experiments have been performed and interestingly the fabricated sensor is efficient in detecting various kinds of breaths such as deep, fast, slow and hydrated breath. The MOF breath sensor shows a fast response time of just ∼0.38 s and excellent stability with no decline in its performance even after a month. A plausible mechanism has been proposed and a smartphone based prototype has been prepared to demonstrate the real time applications of the hybrid device. This work demonstrates great potential for the application of MOFs in healthcare with a special focus on breath sensing and sleep apnea diagnosis.