Origami-inspired GO sheets move in response to light and heat

Scientists at Donghua University in China have found a way to cause tiny (0.8 to 6 centimeter) graphene oxide-based objects to move in specific ways using heat and infrared light. The work was inspired by origami, an art form based on folding paper.

In this work, traditional paper was replaced with two types of graphene sheets infused with hydrogen and oxygen compounds, resulting in graphene oxide and graphene oxide-polydopamine. The former does not react to water but the second does. To create origami type structures, the team infused the latter with water molecules than bonded the two types of sheets together—when heat or light was applied to the second type, it would cause the water molecules to be released, making the paper shrink slightly, which in turn would exert a force that would pull against the second type of sheet. This allowed for the creation of hinges or joints which could be employed on command, which made the objects programmable in a sense.

Read the full story Posted: Nov 11,2015

Boron-doped graphene makes for ultrasensitive gas sensors

An international team of researchers from six countries have designed a highly sensitive gas sensor made from boron-doped graphene, able to detect noxious gas molecules at extremely low concentrations, parts per billion in the case of nitrogen oxides and parts per million for ammonia. These sensors can be used for labs and industries that use ammonia, a highly corrosive health hazard, or to detect nitrogen oxides, a dangerous atmospheric pollutant emitted from automobile tailpipes. In addition to detecting toxic or flammable gases, theoretical work indicates that boron-doped graphene could lead to improved lithium-ion batteries and field-effect transistors. 

The sensor reaches a 27 times greater sensitivity to nitrogen oxides and 10,000 times greater sensitivity to ammonia compared to pristine graphene. The researchers believe these results will open a path to high-performance sensors that can detect trace amounts of many other molecules.

Read the full story Posted: Nov 11,2015

Haydale reports increased revenues and loss in 2015, raises £5.2 million

Haydale reported their financial results for 2015 - revenues reached £644,000 (up from £19,000 in 2014) while total income (which includes government grants) reached £1.48 million (up from £129,000). Most of the increase in income came from EPL Composites (now renamed Haydale Composite Solutions, or HCS) - which generated £1.18 million in income.

Haydale is still losing money - in fact the EBITDA loss rose to £2.38 million (up from a loss of £1.96 million in 2014). Haydale ended the year with only £2.05 million in cash (down from £5.68 million at the end of 2014) - but the company also announced a new share issue that will bring in about £5.2 million. Haydale will sell 3.51 million shares at 160p a share (a 5% discount on the average closing price of Haydale shares in the past 20 days).

Read the full story Posted: Nov 02,2015

A GO-enhanced sensor can detect NO2 level in the atmosphere

A team of researchers from the Indian Institute of Science (IISc) has developed a graphene oxides-based sensor that can detect nitrogen dioxide (NO2) in the atmosphere. The sensor can detect as little as a single NO2 molecule among millions of other molecules and it works even at room temperatures, unlike other common nitrogen sensors that are known to be high temperature devices.

For the development of this sensor, the team used fibre bragg grating, an optical fibre similar to the ones used for communication purposes. However, it can reflect one particular wavelength of light and transmit others. The IISc team covered the fibre bragg grating with an ultra thin layer of reduced graphene oxide and developed the sensor. by modifying the optical fibre, the scientists were able to use it in different applications like gas sensing and bio-sensing.

Read the full story Posted: Nov 02,2015