Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Big breakthrough for tiny particles

MIT chemical engineers have devised an elegant new method for creating complex polymeric microparticles that could have applications in a variety of fields, from drug delivery in medicine to the creation of building blocks for the photonic materials that carry light. The particles can also add texture to skin creams and color to inks.

The new synthesis method gives researchers an extraordinary degree of control over the shape and chemical properties of the microparticles, which range in size from about 1 millionth of a meter to a millimeter.

"We have precise control over shape and an ability to create patterned chemical regions, that is rather unprecedented," said Assistant Professor Patrick Doyle of chemical engineering, one of the authors of a report appearing in the online edition of Nature Materials on April 9.

Doyle says he hopes other researchers will adopt his team’s new technique of continuous flow lithography (CFL), which allows for faster, easier production of microparticles of diverse shape, size and chemical composition.

CFL builds on the well-known technique of photolithography but its novelty lies in the fact that it is performed in a laminar (not turbulent) flowing stream as opposed to the traditionally used stationary film. Wherever pulses of ultraviolet light strike the flowing stream of small building blocks, or oligomers, a reaction is set off that forms a solid polymeric particle in a process known as photopolymerization.

The method makes use of microfluidics - tiny fluid-filled channels with cross-sections typically smaller than a strand of hair. Until now, microfluidic methods have been limited to producing spheres, discs or cylinders. However, with CFL, the particles can be configured into just about any projected 2D shape the researchers want by using a transparency mask to define the shape of a beam of ultraviolet light and focusing it with a microscope. As liquid flows through a microfluidic device, where the synthesis occurs, the shape is repeatedly imprinted onto the oligomer stream, at a rate of about 100,000 particles per hour with the current simple design.

"From an engineering point of view, converting a batch process (photolithography) to a continuous process may have significant advantage when we consider scaling up the technique," said graduate student Dhananjay Dendukuri, lead author on the paper.

The researchers can also create particles with different chemical properties in different locations - for example, a rod that is hydrophilic (water-loving) at one end and hydrophobic (water-fearing) at the other. Such particles are examples of so-called Janus particles, after the Roman god with a double-faced head, and may find use in e-paper technologies or as new building blocks for self-assembled structures.

The new method also makes it easier to create "barcoded" particles, which have an array of chemical properties in different locations. Instead of adding "stripes," or chemical properties, one at a time, the new technique allows them all to be added at once, said Doyle.

Potential medical applications for such particles include drug delivery and performing diagnostic tests, such as testing blood for the presence of certain antibodies or other proteins. Graduate student Daniel Pregibon, one of the authors, said he is interested in creating ring-shaped particles, or "cell cages," that would trap cells for high throughput single cell studies.

Other authors on the paper are Alan Hatton, Ralph Landau Professor of Chemical Engineering Practice, and senior physics major Jesse Collins.

The research was supported by a National Science Foundation grant.

Elizabeth A. Thomson | MIT News Office
Further information:

More articles from Life Sciences:

nachricht ‘Farming’ bacteria to boost growth in the oceans
24.10.2016 | Max-Planck-Institut für marine Mikrobiologie

nachricht Calcium Induces Chronic Lung Infections
24.10.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>