Energy autonomous electronic skin

Energy autonomy is key to the next generation portable and wearable systems for several applications.Among these,the electronic-skin or e-skin is currently a matter of intensive investigations due to its wider applicability in areas,ranging from robotics to digital health,fashion and internet of things(IoT).The high density of multiple types of electronic components(e.g.sensors,actuators,electronics,etc.)required in e-skin,and the need to power them without adding heavy batteries,have fuelled the development of compact flexible energy systems to realize self-powered or energy-autonomous e-skin.The compact and wearable energy systems consisting of energy harvesters,energy storage devices,low-power electronics and efficient/wireless power transfer-based technologies,are expected to revolutionize the market for wearable systems and in particular for e-skin.This paper reviews the development in the field of self-powered e-skin,particularly focussing on the available energy-harvesting technologies,high capacity energy storage devices,and high efficiency power transmission systems.The paper highlights the key challenges,critical design strategies,and most promising materials for the development of an energy-autonomous e-skin for robotics,prosthetics and wearable systems.This paper will complement other reviews on e-skin,which have focussed on the type of sensors and electronics components.

Laser produced electromagnetic pulses: generation, detection and mitigation

This paper provides an up-to-date review of the problems related to the generation,detection and mitigation of strong electromagnetic pulses created in the interaction of high-power,high-energy laser pulses with different types of solid targets.It includes new experimental data obtained independently at several international laboratories.The mechanisms of electromagnetic field generation are analyzed and considered as a function of the intensity and the spectral range of emissions they produce.The major emphasis is put on the GHz frequency domain,which is the most damaging for electronics and may have important applications.The physics of electromagnetic emissions in other spectral domains,in particular THz and MHz,is also discussed.The theoretical models and numerical simulations are compared with the results of experimental measurements,with special attention to the methodology of measurements and complementary diagnostics.Understanding the underlying physical processes is the basis for developing techniques to mitigate the electromagnetic threat and to harness electromagnetic emissions,which may have promising applications.

Magnetic field annihilation and reconnection driven by femtosecond lasers in inhomogeneous plasma

The process of fast magnetic reconnection driven by intense ultra-short laser pulses in underdense plasma is investigated by particle-in-cell simulations. In the wakefield of such laser pulses, quasi-static magnetic fields at a few mega-Gauss are generated due to nonvanishing cross product ▽(n/) × p. Excited in an inhomogeneous plasma of decreasing density, the quasi-static magnetic field structure is shown to drift quickly both in lateral and longitudinal directions. When two parallel-propagating laser pulses with close focal spot separation are used, such field drifts can develop into magnetic reconnection(annihilation) in their overlapping region, resulting in the conversion of magnetic energy to kinetic energy of particles. The reconnection rate is found to be much higher than the value obtained in the Hall magnetic reconnection model. Our work proposes a potential way to study magnetic reconnection-related physics with short-pulse lasers of terawatt peak power only.