Recently, there has been much interest in using lubricated flat and nano-/micro-structured surfaces to achieve extreme liquid-repellency: any foreign droplet immiscible with the underlying lubricant layer was shown to slide off at a small tilt angle $<$ 5$^{\circ}$. This behavior was hypothesized to arise from a thin lubricant overlayer film sandwiched between the droplet and solid substrate, but this has not been observed experimentally. Here, using confocal optical interferometry, we are able to visualize the intercalated film under both static and dynamic conditions. We further demonstrate that the lubricant flow entrained by droplet motion can transform a partially dewetted film into a continuous layer, by generating a sufficient hydrodynamic force to lift the droplet over the solid substrate. The droplet is therefore oleoplaning, akin to tires hydroplaning on a wet road, with minimal dissipative force (down to 0.1 $\mu$N for 1 $\mu$l droplet when measured using a cantilever force sensor) and no contact line pinning. The techniques and insights presented in this study will inform future work on the fundamentals of wetting for lubricated surfaces and enable their rational design

No abstract

Current marine research primarily depends on weighty and invasive sensory equipment and telemetric network to understand the marine environment, including the diverse fauna it contains, as a function of animal behavior and size, as well as equipment longevity. To match animal morphology and activity within the surrounding marine environment, here we show a physically flexible and stretchable skin-like and waterproof autonomous multifunctional system, integrating Bluetooth, memory chip, and high performance physical sensors. The sensory tag is mounted on a swimming crab (Portunus pelagicus) and is capable of continuous logging of depth, temperature, and salinity within the harsh ocean environment. The fully packaged, ultra-lightweight (<2.4 g in water), and compliant "Marine Skin" system does not have any wired connection enabling safe and weightless cuttingedge approach to monitor and assess marine life and the ecosystem's health to support conservation and management of marine ecosystems.

Electronic chips that are commercially available today are durable and long lasting. However, there is a great need for electronic systems that can lose the functionality and struc ture on demand, or after a certain amount of time. Transient electronics is an emerging technology field in which the func tionality of a chip can be altered or completely destroyed in a controlled manner. [1][2][3][4][5][6] Application areas of transient electronics include healthcare where electronic monitoring implants that can be resorbed in the body over time or a network of bio degradable sensors distributed in the environment that can pro vide data for a certain amount of time. [1][2][3][4][5][6][7][8][9][10][11] In today's digital age, the increasing dependence on information also makes us vulnerable to potential invasion of privacy and cyber security. Consider a scenario in which a hard drive is stolen, lost, or misplaced, which contains secured and valuable information. In such a case, it is important to have the ability to remotely destroy the sensitive part of the device (e.g., memory or processor) if it is not possible to regain it. Many emerging materials and even some traditional materials like silicon, aluminum, zinc oxide, tungsten, and magnesium, which are often used for logic processor and memory, show promise to be gradually dissolved upon exposure of various liquid medium. However, often these wet processes are too slow, fully destructive, and require assistance from the liquid materials and their suitable availability at the time of need. This study shows Joule heating effect induced thermal expansion and stress gradient between thermally expandable advanced polymeric material and flexible bulk monocrystalline silicon (100) to destroy highperformance solid state electronics as needed and under 10 s. This study also shows different stimuli-assisted smartphone-operated remote destructions of such complementary metal oxide semiconductor electronics.

CitationNassar JM, Sevilla GAT, Velling SJ, Cordero MD, Hussain MM (2016)