Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Synthetic Cells Shed Biological Insights While Delivering Battery Power

22.10.2009
Trying to understand the complex workings of a biological cell by teasing out the function of every molecule within it is a daunting task. But by making synthetic cells that include just a few chemical processes, researchers can study cellular machinery one manageable piece at a time.

A new paper* from researchers at Yale University and the National Institute of Standards and Technology (NIST) describes a highly simplified model cell that not only sheds light on the way certain real cells generate electric voltages, but also acts as a tiny battery that could offer a practical alternative to conventional solid-state energy-generating devices.

Each synthetic cell built by NIST engineer David LaVan and his colleagues has a droplet of a water-based solution containing a salt—potassium and chloride ions—enclosed within a wall made of a lipid, a molecule with one end that is attracted to water molecules while the other end repels them. When two of these "cells" come into contact, the water-repelling lipid ends that form their outsides touch, creating a stable double bilayer that separates the two cells' interiors, just as actual cell membranes do.

If the researchers only did that much, nothing interesting would happen, but they also inserted into the bilayer a modified form of a protein, alpha-hemolysin, made by the bacterium Staphylococcus aureus. These embedded proteins create pores that act as channels for ions, mimicking the pores in a biological cell. "This preferentially allows either positive or negative ions to pass through the bilayer and creates a voltage across it," LaVan says. "We can harness this voltage to generate electric current."

If the solutions in the two cells start with different salt concentrations, then poking thin metal electrodes into the droplets creates a small battery: electrons will flow through a circuit connected to the electrodes, counterbalancing the ion flow through the channels. As this happens, the ion concentrations in the droplets eventually equalize as the system discharges its electric potential.

Building synthetic versions of complex real cells—such as those that enable an electric eel to zap its prey [see Tech Beat Oct 1, 2008]—is far too difficult a task for now, says LaVan. So the researchers instead created this far simpler system whose performance they could understand in terms a handful of basic properties, including the size of the droplets, the concentration of the aqueous solutions, and the number of ion channels in the barrier between the two cells.

A tiny battery with two droplets, each containing just 200 nanoliters of solution, could deliver electricity for almost 10 minutes. A bigger system, with a total volume of almost 11 microliters, lasted more than four hours. In terms of the energy it can deliver for a given volume, the biological battery is only about one-twentieth as effective as a conventional lead-acid battery. But in its ability to convert chemical into electrical energy, the synthetic cell has an efficiency of about 10 per cent, which compares well with solid-state devices that generate electricity from heat, light, or mechanical stress—so that synthetic cells may one day take their place in the nanotechnology toolbox.

*J. Xu, F.J. Sigworth, and D.A. LaVan. Synthetic Protocells to Mimic and Test Cell Function. Advanced Materials, published online Oct. 1, 2009 (DOI: 10.1002/adma.200901945).

Ben Stein | Newswise Science News
Further information:
http://www.nist.gov

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>