PRINCETON UNIVERSITY, NEW JERSEY, USA: Researchers of Princeton University have invented a detachable tattoo using silk strands pulled from cocoons and gold wires thinner than a spider’s web that sticks on to dental enamel. This could eventually monitor a patient’s health with exceptional sensitivity. The tattoo creates real time, wireless response from a sensor that can be directly interfaced with a variety of biomaterials. It is able to detect very small amounts of bacteria – a characteristic that is critical in treating certain diseases. The technology will be a real breakthrough in harmful bacterial detection and cure. The system also has the ability to supply fast results.

The device is small, flexible and passive, capable of providing real time detection. The researchers designed the device without a power supply. Instead, an external radio transmitter, held nearby the device, delivers a signal that causes the device to resonate and transmit back its information. The antenna coil is what transmits the signal and does not require a battery. The antenna was designed with the gold coil that is big enough to transmit a readable signal, but small enough to fit within the sensor’s compact footprint. The current version of the system can be attached to a cow’s tooth; reducing the size of the sensor in order to fit onto a human’s tooth would require further work.

The team plans to conduct further studies to better understand the adhesion between the tooth enamel and the graphene sensor with the goal of achieving a long lasting bond and enhancing the durability of the system. One of the challenges for a dental system is protecting the sensor from accidental damage like brushing.

This was developed by a team of researchers headed by Michael McAlpine, the paper’s authors included Manu Mannoor, Jefferson Clayton, and Naveen Verma of the Princeton School of Engineering and Applied Science; Amartya Sengupta an associate research scholar in the Department of Geosciences at Princeton; Hu Tao, David Kaplan and Fiorenzo Omenetto of Tufts University; and Rajesh Naik, of the Air Force Research Laboratory. Support for the research was provided by the American Asthma Foundation and the Air Force Office of Scientific Research.