By Janet Fang
Posting in Technology
Researchers have covered plastic and silk threads with temperature sensors and micro-heaters that monitor the wounds and speed up healing.
These electronic surgical sutures (pictured) contain ultrathin silicon sensors integrated on strips, which can be threaded through needles and – in animal tests – be laced through skin, pulled tight, and knotted without degrading the devices. Technology Review reports.
The sutures depend on flexible and stretchy silicon-based devices. The silicon membranes and gold electrodes and wires are a few hundred nanometers thick and patterned like a snake (which helps make the whole thing more flexible).
- Since elevated temperatures indicate infection, the smart stitches can precisely measure temperature with a silicon diode and a platinum nanomembrane resistor.
- They can also deliver heat to a wound site with micro-heaters made of gold filaments that heat up when a current passes through. This can help with healing.
- One day, they could be laden with devices that provide electrical stimulation to heal wounds.
- The electronic threads could also be coated with drug-infused polymers, which would release chemicals when triggered by heat or an electrical pulse.
"Ultimately, the most value would be when you can release drugs from them in a programmed way," says inventor John Rogers at the University of Illinois at Urbana-Champaign. To build the sutures:
The researchers first use chemicals to slice off an ultrathin film of silicon from a silicon wafer. With a rubber stamp, they lift off and transfer the nanomembranes to polymer or silk strips. Then they deposit metal electrodes and wires on top and encapsulate the entire device in an epoxy coating.
The technology, which has been used in inflatable catheters and medical tattoos, is being commercialized by MC10, a Cambridge, Massachusetts–based startup Rogers cofounded.
The work was reported in the journal Small last week.
[Via Technology Review]
Image: D-H Kim et al., Small
Aug 27, 2012