Surface runoff can contain pollutants that water treatment technologies aren’t designed to remove. Until now. Using a mineral-coated sand that destroys organic pollutants, University of California, Berkeley engineers say that they have discovered a safe and environmentally friendly way to clean storm water. By coating plain sand with manganese oxide, the scientists created a material that can help to purify the water. In conjunction with other water purification technologies, this engineered sand could help to generate drinking water from local sources in an integrated and affordable manner.

Engineers from the University of Minnesota say they have successfully 3D printed light receptors onto a curved surface, a critical step in developing bionic eyes that could restore sight to the blind. Starting with a cornea-shaped glass dome, they used multimaterial 3D printing to attach a base ink of silver particles, which dried in place. Photodiodes were then printed atop the silver particles using semiconducting polymers. The diodes convert light into electricity with 25 percent efficiency. The engineers’ next steps include reducing the size of the glass dome, increasing the number of pixels for improved resolution, and improving the light receptors’ performance. Beyond that, they hope to develop a method to 3D print image sensors on a soft material that could be implanted into a living eye.

During each laundry wash cycle, microfibers break off of our clothing and travel through wastewater treatment facilities to flow into rivers and oceans – an average of 81,000 strands of microfiber per fleece jacket per wash. Aquatic animals ingest those tiny pieces of plastic fiber, causing health problems or death. The fibers can be passed to humans who eat the fish or accumulate in the ocean and coastal waterways. Nonprofit Rozalia Project, based in Vermont, has developed Cora Ball to tackle microfiber pollution. Inspired by corals that filter the ocean, and made from 100 percent recycled and recyclable plastic, the ball collects the microfibers in its stalks. If one in 10 US households used a Cora Ball, the company claims that the equivalent of 30 million plastic bottles could be caught and kept out of the water supply annually. The balls, which cost $30 (about 34 euros) each, have been honored in several competitions for plastic pollution solutions.

A team of engineers at Tufts University in Boston has developed a prototype smart bandage to monitor the healing of wounds. To assist the natural healing process, the bandages can deliver customized treatments in response to built-in sensors that track infection and inflammation. Less than 3 mm (0.12 inches) thick, each bandage’s microprocessor analyzes the data from the sensors and heats a hydrogel to release drugs as needed. Using flexible electronics, thermo-responsive drug carriers, and pH and temperature sensors, the smart bandage is a significant upgrade for a treatment that has changed very little across several millennia.

For a sweeter and easier way to monitor heart or brain functions, researchers at Munich’s Technical University have printed highresolution microelectrodes onto ingestible gummy candies and hydrogels for the first time. Hard materials like silicon, typically used for microelectrode arrays, can create health risks inside the body. Soft material, however, can better integrate with the surrounding tissue. Using a high-tech inkjet printer and carbonbased ink to print the sensors onto the gummies is fast and cost-effective. The researchers say that future development of soft electronics could enable onsite monitoring inside the body or serve as a stimulator.