Molybdenum Di-Sulphide (MoS2): A potential challenger to graphene

Sheets of tin sulphide - The diameter of the roll is about 10 times smaller than a human hair.

A team of researchers from the University of Southampton's Optoelectronics Research Centre (ORC) has developed a new way to fabricate a potential challenger to Manchester's Graphene.

Graphene, a single layer of carbon atoms in a honeycomb lattice, is increasingly being used in new electronic and mechanical applications, such as transistors, switches and light sources, thanks to the unprecedented properties it offers: very low electrical resistance, high thermal conductivity and mechanically stretchable yet harder than diamond.

Molybdenum Di-Sulphide (MoS2)

Now, ORC researchers have developed Molybdenum Di-Sulphide (MoS2), a similar material to graphene that shares many of its properties, including extraordinary electronic conduction and mechanical strength, but made from a metal (in this case molybdenum combined with sulphur).

This new class of thin metal/sulphide materials, known as transition metal di-chalcogenides (TMDCs), has become an exciting complimentary material to graphene.

However, unlike graphene, TMDCs can also emit light allowing applications, such as photodetectors and light emitting devices, to be manufactured.

Until recently, fabrication of TMDCs, such as MoS2, has been difficult, as most techniques produce only flakes, typically just a few hundred square microns in area.

Dr Kevin Huang, from ORC who has led the research, explains: "We have been working on the synthesis of chalcogenide materials using a chemical vapour deposition (CVD) process since 2001 and our technology has now achieved the fabrication of large area (>1000 mm2) ultra- thin films only a few atoms thick."

"Being able to manufacture sheets of MoS2 and related materials, rather than just microscopic flakes, as previously was the case, greatly expands their promise for nanoelectronic and optoelectronic applications."

Dr Huang and his team published their findings in the latest issue of the journal Nanoscale.

They are currently working with several UK companies and universities, as well as leading international centres at MIT and Nanyang Technological University (Singapore).

Dr Huang adds: "Our ability to not only synthesise large uniform thin films but also to transfer these films to virtually any substrate has led to increased demand for our materials."

More Information
"Scalable high-mobility MoS2 thin films fabricated by an atmospheric pressure chemical vapor deposition process at ambient temperature" Author: Chung-Che Huang, Feras Al-Saab, Yudong Wang, Jun-Yu Ou, John C. Walker, Shuncai Wang, Behrad Gholipour, Robert E. Simpsond and    Daniel W. Hewaka - Nanoscale, 2014, Advance Article DOI: 10.1039/C4NR04228J - Received 25 Jul 2014

Amsterdam Labs: MX3D-Metal Large scale multi axis 3D printing in metal - Video

Introducing large scale multi axis 3D printing in metal!

To say that the Joris Laarman Lab is an innovative type of group is putting it mildly. The Amsterdam place is described as "an experimental playground set up to study and shape the future.

It tinkers with craftsmen, scientists and engineers on the many new possibilities of upcoming technology."

One such possibility that has captured their attention has been coming up with a technique for large-scale 3D printing without the need for support material.

They have been exploring ways to allow the creation of 3D objects on any work surface, and not requiring additional support structures.

About nine months ago, we got a first look at a freely articulating 3D printer, developed by Joris Laarman Lab in collaboration with the Institute for Advanced Architecture of Catalonia (IAAC).

By extruding a special fast-curing resin with a multi-jointed robotic arm, MATAERIAL (shown here), proposed a "radically new 3D printing method," suitable for "irregular or non-horizontal surfaces." 

Now, the Dutch designer has unveiled his latest breakthrough in liberating digital fabrication from a build platform: As its name suggests, MX3D-Metal can print lines of steel, stainless steel, aluminum, bronze or copper "in mid-air."

"By using innovative extrusion technology," they said, "we are now able to neutralize the effect of gravity during the course of the printing process."

Welcome to the MX3D-Metal 3D printing initiative from the Lab, creating metal structures in mid-air.

The method combines a robotic arm typically used in car manufacturing with a welding machine to melt and deposit metal, to create lines that can be printed horizontally, vertically, or in curves, without the need for support structures.

Adding small amounts of molten metal at a time, lines are printed in mid-air. The team vision is an affordable, multiaxis MX3D tool for workshops around the world.

"Introducing supportless multiaxis metal printing" says the group's promotional video.

The Joris Laarman Lab are developing different kinds of print heads for different kinds of metals.

The Labs spokesperson said that the method makes it possible to create 3D objects on any given working surface independently of its inclination and smoothness in almost any size and shape.

Their work has been in collaboration with Acotech and supported by 3D CAD software company Autodesk.

A gathering point for industrial designers, Core77, recently featured the Jaris Laarman Lab.

"The basic idea is simple: an advanced welding torch on a robot arm that communicates and is controlled by smart software" the Core77 spokesperson commented.

"They have also been working on strategies for the different kinds of 3D-printable lines."

"Vertical, horizontal or spirals call for different settings: pulse time, pause-time, layer height or tool orientation."

"This information will ultimately be incorporated in the software" the Core77 spokesperson continued.

More information: www.core77.com/digital_fabrication/joris_laarmans