If software can recognise a face in an image then why not also assess what emotion that face is showing? A team from MIT created the MindReader system to analyse photos of hundreds or even thousands of faces and determine the mood of a crowd. They speculate that the system could even replace opinion polls, though initially it's being used to change adverts. The MindReader program interprets expressions on the basis of a few seconds of video. It tracks 22 points around the mouth, eyes and nose, and notes the texture, colour, shape and movement of facial features. In tests the software was better than humans at telling joyful smiles from frustrated smiles. I sense you're feeling concerned.


TOW CHAIR: The Independent Wheelchair Assist was designed by a Kiwi for the 2012 James Dyson Award. It's a set of powered wheels with a handlebar that easily attach to a manual wheelchair. That means the user doesn't have to transfer from a manual wheelchair to a mobility scooter for longer journeys. The device locks onto the wheelchair and then tows it safely. That's a clever idea. James Dyson Foundation has more.


SOLID SOLAR: Solar cells cost a lot to produce and are fairly inefficient. Researchers at Northwestern University created a robust novel material that uses millions of light-absorbing nanoparticles to make a solid-state solar cell. The cells use a compound of cesium, tin and iodine and are efficient, stable and long-lasting. Individual cells are 10 microns thick and measure around half a centimetre on each side. Every increase in efficiency and reduction in price is a good one. Northwestern University has further information.

POWER WASHER: Solar panels aren't incredibly efficient anyway, but add a coating of dust and grime and efficiency plummets. Students from CalTech and UCLA created the Greenbotics robot that uses sprayers, brushes and squegees to clean large arrays of solar panels. Once the robot is placed on a row of panels it traverses them autonomously, cleaning as it goes. An operator can control the robot wirelessly. It beats going out there with a brush on a pole. Greenbotics details.

QUICK KEYS: A minuteKEY kiosk can duplicate most keys in moments. Choose options, such as how many copies you need, insert the key and pay by credit card. Moments later the duplicates pop out. A viewing window lets you watch the copying process as the kiosk works. Sounds simple. minuteKEY elaborates. Check out the video here.

Miraz Jordan,