Laser Direct Writing of Flexible Thermal Flow Sensors

Abstract

Thin film-based thermal flow sensors afford applications in healthcare and industries owing to their merits in preserving initial flow distributions. However, traditional thermal flow sensors are primarily applied to track flow intensities based on hot-wire or hot-film sensing mechanisms due to their relatively facile device configurations and fabrication strategies. Herein, a calorimetric thermal flow sensor is proposed based on laser direct writing to form laser-induced graphene as heaters and temperature sensors, resulting in monitoring both flow intensities and orientations. Via homogeneously surrounding spiral heaters with multiple temperature sensors, the device exhibits high sensitivity (∼162 K·s/m) at small flows with an extended flow detection range (∼25 m/s). Integrating the device with a data-acquisition board and a dual-mode graphical user interface enables wirelessly and dynamically monitoring respiration and the motion of robotic arms. This versatile flow sensor with facile manufacturing affords potentials in health inspection, remote monitoring, and studying hydrodynamics.

Multi-interface Combination of Bimetallic Selenide and V4C3Tx MXene for High-Rate and Ultrastable Sodium Storage Devices

“…Recently, two-dimensional (2D) transition metal–carbon nitrides (MXenes) attracted considerable attention for electrochemical energy storage applications due to its layered structures, charming electrical conductivities, abundant functional groups, and high specific surface areas. , Among them, V 4 C 3 T x stands out because of its multilayered structure, which provides better thermal stability and higher electrical conductivity than other MXene materials (Figure S1 and Supplementary Note S1). , However, random distribution of terminal groups (such as hydroxyl and fluorine anions) on the MXene surface leads to an uneven surface charge distribution, which hinders interfacial cross-linking between adjacent MXene sheets .…”

Soft actuators based on the flexible MOF MIL-88B(Fe) with a fast response to various organic solvent vapours

“…Inspired by the easy fabrication of the LIG sensor, a LIG methanol sensor was fabricated by coating a mixture of MIL-88B and PVDF in DMF to the LIG surface. 51–54 Interestingly, although the coating was very thin and the solvent-driven deformation of the LIG was tiny to the naked eye (Fig. 7(D)), it was sensitive enough to methanol vapor that the introduction of 1 vol% methanol gas led to an approximately 400 Ohm decrease in the resistance.…”

All-Optical Diffractive Deep Neural Networks Enabled Laser-Reduced Graphene Oxide Tactile Sensor for Braille Recognition

“…In recent years, laser-reduced graphene oxide (LRGO) films have attracted considerable attention in the field of sensor applications due to their outstanding surface area, thermal stability, and conductivity. , In particular, multifunctional flexible sensors based on LRGO have been developed to detect physical, chemical, and electrophysiological signals simultaneously. − Laser reduction technology offers unique advantages, including selective and localized reduction, precise and rapid patterning, and the absence of the need for masks and additional chemical substances. − Moreover, the entire laser reduction process takes only a few minutes, significantly enhancing the preparation efficiency of flexible tactile sensors . Simultaneously, the layered structure of molybdenum disulfide (MoS 2 ) allows for the incorporation of external atoms. , Recently, electronic devices utilizing tactile sensors for Braille character recognition have been developed to improve the communication and reading skills of the blind. , …”