The flexible device on a finger.
Credit: Image courtesy of RIKEN

Scientists have developed a human-friendly, ultra-flexible organic sensor powered by sunlight, which acts as a self-powered heart monitor. Previously, they developed a flexible photovoltaic cell that could be incorporated into textiles. In this study, they directly integrated a sensory device, called an organic electrochemical transistor – a type of electronic device that can be used to measure a variety of biological functions – into a flexible organic solar cell. Using it, they were then able to measure the heartbeats of rats and humans under bright light conditions.

Self-powered devices that can be fit directly on human skin or tissue have great potential for medical applications...

A global dust storm completely obscured the surface of Mars. Images from May 28 and July 1.
Credit: NASA/JPL-Caltech/MSSS

When dust filled the Martian atmosphere during the recent planet-wide dust storm, observations were plentiful – even from unlikely instruments. NASA’s Mars Reconnaissance Orbiter (MRO) provided the earliest insights on May 30 when it observed an accumulation of dust in the atmosphere near Perseverance Valley, where NASA’s Opportunity rover is exploring. The increasingly hazy storm, the biggest since 2007, forced Opportunity to shut down science operations by June 8, given that sunlight couldn’t penetrate the dust to power the rover’s solar panels. Scientists are anxiously waiting for the roving explorer to regain power and phone home.

Meanwhile, on June 5, evidence quiet...

When exposed to the sky, the porous polymer PDRC coating reflects sunlight and emits heat to attain significantly cooler temperatures than typical building materials or even the ambient air.
Credit: Jyotirmoy Mandal/Columbia Engineering

Engineers have invented a high-performance exterior PDRC polymer coating with nano-to-microscale air voids that acts as a spontaneous air cooler and can be fabricated, dyed, and applied like paint on rooftops, buildings, water tanks, vehicles, even spacecraft – anything that can be painted. They used a solution-based phase-inversion technique that gives the polymer a porous foam-like structure.

With temperatures rising and heat-waves disrupting lives around the world, cooling solutions are becoming ever more essential...

A snapshot from a simulation of the churning gas that blankets a star 80 times the sun’s mass. Intense light from the star’s core pushes against helium-rich pockets in the star’s exterior, launching material outward in spectacular geyser-like eruptions. The solid colors denote radiation intensity, with bluer colors representing regions of larger intensity. The translucent purplish colors represent the gas density, with lighter colors denoting denser regions. Credit: Joseph Insley/Argonne Leadership Computing Facility

New, 3D simulations reveal the inner workings of one of the universe’s most mysterious stars...