Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Micro-onions and Magnetic Ink

Microfluidic systems for the easy production of multiphasic emulsion drops and multishelled polymer capsules

Under a microscope they look like miniature onions, in fact, they are new microcapsules introduced by David A. Weitz and Shin Hyun Kim in the journal Angewandte Chemie. The researchers from Harvard University in Cambridge (Massachusetts, USA) have developed a simple method that makes it possible to produce these tiny shell-like objects with a microfluidic system in just one step. Possible applications include magnetic inks and transport systems for multicomponent pharmaceuticals.

By using a sophisticated microfluidic system that consists of multiple glass capillaries with water-repellent and water-attracting coatings, the researchers are able to get opposing streams of immiscible liquids (oil and water) to collide. Tiny droplets are formed as the resulting stream passes through an opening into a collection capillary. Within the droplets, the phase boundaries between the liquids are cleverly disrupted so that—depending on the structure of the system—three- or four-layer emulsion drops are formed. This process is the first to make it possible to produce large numbers of multiwalled emulsion drops of uniform size and structure.

As a sample application, Weitz and Kim produced a “magnetic ink” for displays. The oily phase was a solution of a UV-crosslinking polymer. The researchers produced emulsion drops with a core of polymer solution surrounded by a shell of water, which is in turn contained in another shell of polymer solution. They mixed magnetic particles and black pigments into the polymer solution that makes up the core and added tiny particles of plastic to the aqueous liquid.

After irradiation with UV light, they obtained transparent capsules with a solid shell and a solid, black core that floats freely in the aqueous layer with the plastic particles. In the absence of a magnetic field, the black cores remain at the center of the capsules. A layer of such capsules in a display appears white because the plastic particles scatter light. When a magnetic field is applied, the cores are pulled toward the surface of the display, making the black color visible.

Another practical application for multilayer capsules is the transport of multicomponent pharmaceuticals that would remain separate until sequentially released on target in the body.

Author: Shin-Hyun Kim, Harvard University,
Title: One-Step Emulsification of Multiple Concentric Shells with Capillary Microfluidic Devices

Angewandte Chemie International Edition, Permalink to the article:

Shin-Hyun Kim | Angewandte Chemie
Further information:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

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

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>