Electronic membrane monitors and treats patients through skin
4 December 2013
An international team has developed an electronic circuit on a
flexible membrane that adheres non-invasively to human skin and can
contain a range of microdevices for sensing or delivering stimuli or
The technology is a variation of a novel technology, originally
developed in the lab of Professor John Rogers at the University of
Illinois at Urbana/Champaign, called 'epidermal electronics'
consisting of ultrathin, flexible skin-like arrays, which resemble a
tattoo of a micro-circuit board. The arrays in this study, developed
with the US National Institute of Biomedical Imaging and
Bioengineering (NIBIB), contain sensors and heating elements.
The development of this new thermal technology was reported
in the October 23 issue of Nature Materials.
In this study, the array contained heat sensors so that it could
be tested for its ability to accurately detect variations in
localized skin temperature when compared to the 'gold standard'
infrared camera. A number of separate physical and mental stimulus
tests were performed to compare the two. The subject wore a heat
sensing array on the palm and also had heat measurements obtained
with an infrared camera placed 16 inches above the same region. The
profiles of temperature changes were virtually identical with the
Components of a 1x2 cm array include
an antenna, power coils, and temperature sensors.
The investigators also performed a test that is used as a
cardiovascular screening procedure. Blood flow changes are detected
by changes in skin temperature as blood moves through the forearm
while a blood pressure cuff on the upper arm is inflated and
deflated. Once again, the infrared camera and the array technology
showed virtually identical temperature change profiles. Temperature
was reduced when blood flow was blocked and it increased as blood
was released. Slow return of blood to the forearm can indicate
potential cardiovascular abnormalities.
Beyond serving as a test to validate the accuracy of the skin
array, this experiment demonstrated that the device could
potentially be used as a rapid screening tool to determine whether
an individual should be further tested for disorders, such as
diabetes or cardiovascular disease, that cause abnormal peripheral
blood flow. It could also be a signal to doctors and patients about
effects of certain medications.
The final experiment addressed a feature unique to the skin array
technology: delivery of a stimulus, such as heat. The researchers
sent precise pulses of heat to the skin to measure skin
perspiration, which indicates a person’s overall hydration. Taken
together, the test results demonstrated the ability of the array
technology to obtain a range of accurate, clinically useful
measurements, and deliver specific stimuli, with a single,
convenient, and relatively inexpensive device.
The researchers say the current version of the array that senses
and delivers heat only hints at the vast possibilities for this
technology. For example, in theory, any type of sensor can be
included, such as sensors that reveal glucose levels, blood oxygen
content, blood cell counts, or levels of a circulating medication.
Also, instead of delivering heat, an element could be included in
the circuit that delivers a medication, an essential micro-nutrient,
or various stimuli to promote rapid wound healing. This ability to
sense and deliver a wide range of stimuli makes the system useful
for diagnostic, therapeutic and experimental purposes.
The technology has the potential to carry out such therapeutic
and diagnostic functions while patients go about their daily
business, with the data being delivered remotely via a cell phone
directly to a doctor — saving the expense of obtaining the same
diagnostic measurements, or performing the same therapeutic
stimulus, in the clinic.
Alexander Gorbach, Ph.D., one of the co-investigators from NIBIB,
and head of the Infrared Imaging and Thermometry Unit, says, “We are
very excited about the unique potential of this technology to vastly
improve healthcare at multiple levels. Continuous monitoring outside
of a hospital setting will be more convenient and cost-effective for
patients. Additionally, access to data collected over extended
periods, while a patient is going about a normal routine, should
improve the practice of medicine by enabling physicians to adjust a
treatment regimen ‘24/7’ as needed.”
The investigators are already receiving requests from other
clinical research labs to use this technology, and plan to expand
collaboration with academia and industry. The hope is that the
research community’s interest in epidermal electronics will
accelerate the development and validation of this technology and
hasten its incorporation into clinical care.
1. Webb RC, et al. Ultrathin conformal devices for
precise and continuous thermal characterization of human skin. Nat
Mater. 2013 Oct 23;12(11):1078. doi: 10.1038/nmat3779. PMID: