Smart fingertips - Seminar topic

Abstract

We describe the use of semiconductor nanomaterials, advanced fabrication methods and unusual device designs for a class of electronics capable of integration onto the inner and outer surfaces of thin, elastomeric sheets in closed-tube geometries, specially formed for mounting on the fingertips. Multifunctional systems of this type allow electrotactile stimulation with electrode arrays multiplexed using silicon nanomembrane (Si NM) diodes, high-sensitivity strain monitoring with Si NM gauges, and tactile sensing with elastomeric capacitors. Analytical calculations and finite element modeling of the mechanics quantitatively capture

the key behaviors during fabrication/assembly, mounting and use. The results provide design guidelines that highlight the importance of the NM geometry in achieving the required mechanical properties. This type of technology could be used in applications ranging from human–machine interfaces to ‘instrumented’ surgical gloves and many others.

Electronic Finger Electronic fingertips could give robots a sense of touch, or allow doctors to operate via virtual touch. John Rogers/University of Illinois

For More Reference

http://rogers.matse.illinois.edu/files/2012/nanotechfingertip.pdf

Imagine feeling like you’re lifting a 50-kilogram weight just by pulling at thin air. That’s just one of the possible applications of new "smart fingertips" created by a team of nanoengineers. The electronic fingers mold to the shape of the hand, and so far the researchers have shown that they can transmit electric signals to the skin. The team hopes to one day incorporate the devices into a smart glove that creates virtual sensations, fooling the brain into feeling everything from texture to temperature.

Scientists have already developed circuits that stimulate our sense of touch. Some are used in Braille readers that allow blind people to browse the Internet. The devices work by sending electric currents to receptors in the skin, which interpret them as real sensations. However, most of these circuits are built on flat, rigid surfaces that can’t bend, stretch, or fold, says Darren Lipomi, a nanoengineer at the University of California, San Diego, who was not involved in the new study.

Hoping to create circuits with the flexibility of skin, materials scientist John Rogers of the University of Illinois, Urbana-Champaign, and colleagues cut up nanometer-sized strips of silicon; implanted thin, wavy strips of gold to conduct electricity; and mounted the entire circuit in a stretchable, spider web-type mesh of polymer as a support. They then embedded the circuit-polyimide structure onto a hollow tube of silicone that had been fashioned in the shape of a finger. Just like turning a sock inside out, the researchers flipped the structure so that the circuit, which was once on the outside of the tube, was on the inside where it could touch a finger placed against it.

To test the electronic fingers, the researchers put them on and pressed flat objects, such as the top of their desks. The pressure created electric currents that were transferred to the skin, which the researchers felt as mild tingling. That’s a first step in creating electrical signals that could be sent to the fingers, which could virtually recreate sensations such as heat, pressure, and texture, the team reports online today inNanotechnology.

The work is "a striking achievement," Lipomi says, who notes that the device could have lots of applications. "In a virtual world, a trainee could perform virtual surgery, in which the devices were used to trick the trainee’s brain into believing they were actually performing a delicate task."

Rogers says another application of the technology is to custom fit the "electronic skin" around entire organs, allowing doctors to remotely monitor changes in temperature and blood flow. Electronic skin could also restore sensation to people who have lost their natural skin, he says, such as burn victims or amputees.