Researchers have now coated sutures with sensors that could monitor wounds and speed up healing.
The electronic sutures, which contain ultrathin silicon sensors integrated on polymer or silk strips, can be threaded through needles, and in animal tests researchers were able to lace them through skin, pull them tight, and knot them without degrading the devices.
The sutures can precisely measure temperature—elevated temperatures indicate infection—and deliver heat to a wound site, which is known to aid healing. And John Rogers, professor of materials science and engineering at the University of Illinois at Urbana-Champaign and inventor of the smart sutures, imagines that they could also be laden with devices that provide electrical stimulation to heal wounds. “Ultimately, the most value would be when you can release drugs from them in a programmed way,” he says. The researchers could do that by coating the electronic threads with drug-infused polymers, which would release the chemicals when triggered by heat or an electrical pulse.
Stitches that sense: New smart sutures use ultrathin silicon sensors to measure temperature at a wound site. John Rogers
The smart sutures rely on silicon-based devices that flex and stretch. Rogers and his colleagues make the devices with silicon membranes and gold electrodes and wires that are just a few hundred nanometers thick and patterned in a serpentine shape. The technology, which they have also used in inflatable catheters and medical tattoos, is being commercialized by MC10, a Cambridge, Massachusetts–based startup Rogers cofounded.
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.
ABSTRACT – Proper healing of incised skin is critical to the natural processes of tissue repair. Concepts in flexible silicon electronics enable integration of actuators, sensors and a variety of semiconductor devices onto thin strips of plastic or biopolymers, to yield ‘instrumented’ suture threads for monitoring and accelerating the wound healing in this context. Bifacial systems of this type demonstrate various classes of functionality, in live animal models. Detailed modelling of the mechanics reveals stress and strain distributions in such applications, to support design strategies for robust operation.
mc10 is a company developing the next generation of electronic systems through its Conformal Electronics Platform. mc10’s platform enhances and enables new applications by allowing high performance electronics to occupy spaces and geometries not possible in their traditional, rigid form. Backed by an extensive patent portfolio secured both through in-licensing and continued developments at mc10, the company is targeting applications in consumer electronics, medical devices, industrial products, and defense systems. mc10’s technology platform uses standard tools and processes and combines the performance of traditional semiconductors with the mechanical properties of elastomeric (stretchable) materials.
mc10 technology uses conventional, high performance (over GHz) semiconductors in conjunction with a proprietary interconnect and packaging technology to produce high yield, low cost, conformal electronics. All of our materials and processes are compatible with industry standard CMOS production facilities.