Science in Brief
Security flaws in smart home products discovered
Smart home products such as lamps controlled via mobile devices are becoming ever more popular in private households. However, researchers at the IT Security Infrastructures group, Friedrich-Alexander University Erlangen-Nürnberg (FAU) in Germany have discovered security problems in smart lights from many of the major manufacturers on the market.
The team managed to make connected lighting systems from different manufacturers flash for several hours with a single radio command sent from a distance of more than 100 m away. Additionally, they were able to modify the bulbs using radio commands so that the user was unable to control them. It was even possible in certain situations to change the colour or brightness of the light.
The FAU researchers discovered the security weaknesses in ZigBee, an important wireless standard employed for the control of smart home products. More than 100 million products that use ZigBee technology are estimated to have been distributed around the world. The most recent version, ZigBee 3.0, was released in December 2016. Part of this specification includes the touchlink commissioning procedure for adding new devices to an existing smart home network or to set up a new network. The team was able to demonstrate that the security features of touchlink commissioning are inadequate and make it vulnerable to attack. It is probable that other applications based on ZigBee that are relevant to security, such as heating systems, door locks and alarm systems, will also be affected in the future.
The research team recommended disabling touchlink commissioning in all future ZigBee 3.0 products. The latest information is published on the following website: www1.informatik.uni-erlangen.de/content/zigbee-security-research.
Smartphone screen technology used to trick harmful bacteria
Conducting plastics found in smartphone screens can be used to trick the metabolism of pathogenic bacteria, report scientists at the Swedish Medical Nanoscience Centre at Karolinska Institute. By adding or removing electrons from the plastic surface, bacteria may be tricked into growing more or less.
When bacteria attach to a surface they grow quickly into a biofilm, which can be dangerous, especially in a hospital setting where they can cause life-threatening infections. Researchers are looking to address this problem by producing coatings for medical devices made from a cheap conducting plastic called PEDOT, which is what makes smartphone screens respond to touch. By applying a small voltage, the PEDOT surface was either flooded with electrons or left almost empty, which in turn affected the growth of salmonella bacteria.
"When the bacteria land on a surface full of electrons, they cannot replicate," explains principal investigator Prof Agneta Richter-Dahlfors, director of the Swedish Medical Nanoscience Centre. "They have nowhere to deposit their own electrons which they need to do in order to respire."
On the other hand, if the bacteria encountered an empty PEDOT surface, the opposite happened and they grew to a thick biofilm.
The research team therefore could either stop bacterial growth - by coating medical devices to make them more resistant to colonisation by bacteria for example - or let it continue. The latter would be useful for industries like wastewater management where beneficial biofilms are used to make clean water.
In the future the research team wants to integrate this technology with devices that could one day be implanted into patients to keep them safe when undergoing medical procedures or having devices implanted.
New way to make dissolving electronics
Researchers from the University of Houston in the US and China have reported a new type of electronic device that can be triggered to dissolve through exposure to water molecules in the atmosphere.
The work holds promise for eco-friendly disposable personal electronics and biomedical devices that dissolve within the body. There are also defence applications, including devices that can be programmed to dissolve in order to safeguard sensitive information.
The field, known as physically transient electronics, currently requires immersion in aqueous corrosive solutions or biofluids. The team's work, however, demonstrates a completely new working mechanism: the dissolution is triggered by ambient moisture. Functional electronic components are built via additive processes onto a film made of the polymer polyanhydride. The device remains stable until ambient moisture triggers a chemical breakdown that digests the inorganic electronic materials and components. The lifespan of the devices can be controlled by varying the humidity level or by changing the polymer composition.
The researchers tested a number of compounds, including aluminium, copper, nickel indium-gallium, zinc oxide and magnesium oxide, and developed various electronic devices, including resistors, capacitors, antennas, transistors, diodes, photo sensors and more, to demonstrate the model's versatility.