We report the morphology-controlled synthesis of aluminium (Al) doped zinc oxide (ZnO) nanosheets on Al alloy (AA-6061) substrate by a low-temperature-solution growth method without using any external seed layer and doping process.

The discovery of stable two-dimensional (2D) materials has effectuated a rapid evolution of skin conformal sensors for health monitoring via epidermal electronics. Among the newly discovered 2D materials, MXene stands out as a solutionprocessable 2D material allowing easy fabrication of highly conductive thin films with the potential to realize flexible skin conformal sensors. Here, we present a successful demonstration of a Ti 3 C 2 −MXene resistor as an extremely sensitive strain sensor in the form an ultrathin skin mountable temporary tattoo. The skin conformability and form factor afforded by the sensor promises inconspicuous and continuous monitoring of vital health parameters of an individual, like the pulse rate, respiration rate, and surface electromyography. The sensor serves as a single conduit for sensing the respiration rate and pulse, dispensing with the need of mounting multiple sensors. Its remarkably high sensitivity with a gauge factor of ∼7400 has been ascribed to development of nanocracks and their propagation through the film upon application of strain. The fast response and highly repeatable sensor follows easy fabrication steps and can be patterned into any shape and size using a laser.

The current pandemic has forced the healthcare system into a transformation where the patients are required to be continuously monitored without the need for hospitalization. The advances in wearable sensors...

We discuss here the realization of tactile sensors based on the principle of change in piezoelectric resonance frequency with the applied pressure. An array of electrodes has been adopted on either side of the PZT material to have independent resonators. The common areas sandwiched between the electrodes and excitable at resonance frequency of the PZT material are used to form the sensitive area of the tactile sensor. The electrodes were deposited using sputtering technique. Tactile sensors with 3 3, 7 7, and 15 15 array of electrodes are developed with different electrode dimensions and separation between the electrodes. The tactile sensor has been interfaced to computer for the convenience of automatic scanning and making it more user interactive. The tactile sensors developed with different spatial resolution were tested for different shaped objects placed in contact with the sensor. The 3 3 matrix tactile sensor showed relatively poor spatial resolution, whereas the 15 15-matrix tactile sensor showed improved spatial resolution. The sensor with 7 7 matrix elements was tested for its sensitivity to different extents of applied force/pressure. The output response study carried out on the sensors indicated that these sensors can provide information not only about the extent of force/pressure applied on the object, but also the contour of the object which is in contact with the sensor. Index Terms-Piezoelectric resonance and robotics, tactile sensor. G. Murali Krishna was born in 1975 in India. He received the M.Sc. degree in electronics from the School of Physics, University of Hyderabad, India, and the M.Sc. (Engg.) degree from the Department of Instrumentation, Indian Institute of Science, Bangalore, where he was involved in the development of tactile sensors. His thesis was titled "Development of tactile sensors based on piezoelectric resonance and surface acoustic waves." He is currently pursuing the Ph.D.degree in nanotechnology-based cantilever sensors at

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A novel fabrication process has been described for the development of a hollow stainless steel microneedle array using femto second laser micromachining. Using this method, a complicated microstructure can be fabricated in a single process step without using masks. The mechanical stability of the fabricated microneedle array was measured for axial and transverse loading. Skin histology was carried out to study the microneedle penetration into the rat skin. Fluid flow through the microneedle array was studied for different inlet pressures. The packaging of the microneedle array, to protect the microneedle bore blockage from dust and other atmospheric contaminations, was also considered. Finally, the microneedle array was tested and studied in vivo for insulin delivery to a diabetic rat. The results obtained were compared with the standard subcutaneous delivery with the same dose rate and were found to be in good agreement.

We discuss here about the realization of tactile sensor based on the principle of change in piezoelectric resonance frequency with the applied pressure. An array of electrodes has been adopted on either side of the PZT material to have independent resonators. The common areas sandwiched between the electrodes and excitable at resonance frequency of the PZT material are used to form the sensitive area of the tactile sensor. The electrodes were deposited using sputtering technique.Tactile sensors with 3x3, 7x7 and 15x15 array of electrodes are developed with different electrode dimensions and separation between the electrodes. The tactile sensor has been interfaced to computer for the convenience of automatic scanning and making it more user interactive. The tactile sensors developed with diflerent spatial resolution were tested for diferent shaped objects placed in contact with the sensor. The 3x3 matrix tactile sensor showed relatively poor spatial resolution whereas I.5xlS-matrix tactile sensor showed improved spatial resolution. The sensor with 7x7 matrix elements was tested for its sensitivity to different extents of applied force/pressure. The output response study carried out on the sensors indicated that these sensors can provide information not only about the extent of force/pressure applied on the object, but also the contour of the object which is in contact with the sensor.