Long Term Implantable Bio-Sensors Developed Using Carbon Nanotubes

Using carbon nanotubes, scientists have developed a biosensor that can be implanted under the skin that will last more than a year. They have also developed a short term biosensor that can travel through the blood stream flowing through the different organs of the body without causing damage.

In order to get a reading and collect data from the sensors, a laser that produces near-infrared light is used to detect the fluorescent signal off of the nanotube based devices.

The long term biosensor was made to detect nitric oxide (NO) levels in the body for monitoring cancerous cells. This is the first time that implantable nanosensors could be used within the body for this extended period of time.

For the biosensor to last under the skin, it is embedded in a gel made from a polymer called alginate for protection.

This application is not limited to NO detection, it can also be used to detect glucose (blood sugar) levels in the body for monitoring diabetes.

Stretchable Lithium Ion Battery Developed For Use In Implantable Electronic Biodevices

A lithium ion battery that can be stretched, bent, and twisted has been developed. These batteries can be used in implantable biological devices where size and shape of current batteries would be an issue in its performance and application.

Lithium ion batteries are the most popular type of batteries used for electronic devices. Li-ion batteries can be comprised of smaller units called cells.

Electrical current reaches the cells by conductive surfaces usually made up of aluminum on one side and copper on the other side. The battery is made up of a positive and negative electrode called the cathode and the anode.

The positive electrode (cathode) is made of lithium metal oxide. On the other side of the battery lies the negative electrode (anode) and is made up of graphite.

In the middle of the cathode and anode is the electrolyte. This allows the lithium ions carrying the electrical charge to flow freely from the anode to the cathode. It also allows transport of ions from the cathode to the anode during the charging process.

Li-ion batteries are popular because of their proven track record in long battery life and battery performance due to their energy density slow loss of charge when not in use.