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Surgical gloves are worn by all types of health care
professionals to keep both the patient and the caregiver safe. Recently a group of
scientists have developed an advanced sensing platform that fits like a
glove.
Image Credit:
gloveuniversity.com
The new
sensing platform is built into silicon nanomembranes and is capable of
responding with high precision to the stresses and strains associated with
touch and finger movement. The electronic, or active, components use advanced
machine design and are made of patterns of gold conductive lines and ultrathin
sheets of silicon, integrated onto a flexible polymer polymide. The mesh
structure is then printed onto silicon rubber via a process called transfer
printing. The ultrathin, stretchable, elastomeric sheets of rubber are molded
into a finger-tube shape so it can easy fit on a fingertip. Transfer printing
delivers the device mesh structure to the outer surface of the finger-tube,
while pressed into a flattened geometry.
The multifunction devices have an electrotactile
stimulator on the inside, and strain gauge arrays and tactile sensors on the
outside. The electronics are capable of accommodating large strains induced by
natural deformation of the fingertip tube and, unique to this device, when the
tube is flipped inside out. The "flipping over" process allows sensors to
function on the outer surface of the tube as well as the inner surface, where
they can press directly against the skin when mounted on the finger.
Image
Credit:Nanotechnology
Electrotactile stimulation allows information to be
presented through the skin. The artificial sensation of touch is perceived as a
vibration or tingling feeling. The stresses and strains are measured via
changes in capacitance of pairs of microelectrodes in the circuit. Tactile
sensors are used to measure the pressure created by physical contact and
provide information for feedback loops with the electrotactile process. The
fingertip tactile sensors can also include sensors for motion and temperature.
The applications for this type of device overlap with
simulated surgery, therapeutic devices, robotic manipulation, and more. Adaptation
from well-developed techniques means that the fabrication process can be scaled
for realistic use at a reasonable cost. Challenges include creating new
materials and schemes to supply wireless data and power to the device. The next
step for this team is to create a "skin" for integration on other parts of the
body, such as the heart, which would envelop the entire surface of the heart to
deliver various sensing and actuating functions to provide diagnostic
information.
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