June 25, 2014
Detecting Emotions By Reading Goose Bumps
Rebekah Eliason for redOrbit.com - Your Universe Online
Emotions are often considered relative states that are difficult to measure. It may not be far off in the future, however, when scientists will be able to quantify emotional states. A team of researchers at KAIST in Daejeon, South Korea have developed a sensor that can directly measure the degree and occurrence of goose bumps, technically known as piloerection. This wearable device measures 20mm x 20mm.Goose bumps occur because of sudden changes in body temperature and emotional states. The technology for this sensor is based on a coplanar capacitor that can detect goose bumps by using a simple linear relation between the deformation of the sensor and the decrease of the capacitance.
"We found that the height of the goose bump and the piloerection duration can be deduced by analyzing obtained capacitance change trace," explained KAIST's Young-Ho Cho.
Although it will take much more work to correlate physical measurements with emotional states, the study suggests that attaining quantitative measurements of goose bumps to indicate human physical and emotional states is possible. This new technology could lead to personalized advertising, music streams or other services informed by direct access to the user’s emotions.
"In the future, human emotions will be regarded like any typical biometric information, including body temperature or blood pressure," Cho said.
The capacitor was built using microfabrication technology and a flexible polymer material embedded with a silicon substrate using a multi-step spin-coating process. This gave the sensor a spiral shape, coplanar structure, a high capacitive density and high deformability all while remaining only 1.2 micrometers thick.
Since the sensor is highly thermal and is photostable, the embedded polymer devices can perform in a wide array of conditions. The silicon substrate was specifically chosen for it biocompatibility and high flexibility relative to human skin.
In this study, the sensors were attached to the inside of a 28-year-old participant’s dorsal forearm. He was then instructed to grab ice cubes in order to induce a sudden cold shock. This stimulated piloerection and cause deformation of the sensors which in turn caused a notable decrease in their capacitance.
In the future, the team intends to scale down the signal processing module and capacitance measurement system so it can be co-mounted on skin with the sensor.
This study was published June 24, 2014 in the Applied Physics Letters.
Image 2 (below): The Goose Bump Detector is a skin piloerection monitoring sensor conformally attached to the dorsal forearm. Credit: Young-Ho Cho/KAIST