‘Smart fingertips’ could allow for virtual surgery

August 12, 2012

Electronic fingertips could one day allow doctors or robots to operate by virtual touch (credit: John Rogers/University of Illinois at Urbana-Champaign)

Semiconductor devices capable of responding with high precision to touch and finger movement are a step towards creating surgical gloves for use in medical procedures such as local ablations and ultrasound scans.

Researchers from the University of Illinois at Urbana-Champaign, Northwestern University and Dalian University of Technology used ultrathin, stretchable, silicon-based electronics and soft sensors mounted onto an artificial “skin” and fitted to fingertips.

The team hopes to incorporate the devices into a smart glove with the flexibility of skin that creates virtual sensations of everything from texture to temperature.

“Imagine the ability to sense the electrical properties of tissue, and then remove that tissue, precisely by local ablation, all via the fingertips using smart surgical gloves,” said co-author of the study Professor John Rogers.

The researchers suggest that the new technology could also allow a trainee to perform virtual surgery or lead to surgical robots that can interact with their surroundings through touch.

How it works

The electronic circuit on the “skin” is made of patterns of gold conductive lines and ultrathin sheets of silicon, integrated onto a flexible polymer called polyimide. The sheet is then etched into an open mesh geometry and transferred to a thin sheet of silicone rubber moulded into the precise shape of a finger.

This electronic “skin,” or finger cuff, was designed to measure the stresses and strains at the fingertip by measuring the change in capacitance — the ability to store electrical charge — of pairs of microelectrodes in the circuit.

It uses electrode arrays multiplexed using silicon nanomembrane diodes and gauges, and does tactile sensing with elastomeric capacitors (applied force decreases the spacing, which, in turn, increases the capacitance, which can be used in generating a signal).

The fingertip device could also be fitted with sensors for measuring motion and temperature, with small-scale heaters as actuators for ablation and other related operations

The researchers believe that because the device exploits materials and fabrication techniques adopted from the established semiconductor industry, the processes can be scaled for realistic use at reasonable cost.

The researchers also intend to create a “skin” for other parts of the body, such as the heart.  In this case, a device would envelop the entire 3D surface of the heart, like a sock, to provide various sensing and actuating functions, providing advanced surgical and diagnostic devices relevant to cardiac arrhythmias.

Future challenges include creating materials and schemes to provide the device with wireless data and power.