sff conference final poster
TRANSCRIPT
An Easy Releasable, Perforated Elastomer Membrane for
Epidermal Electronic DevicesHubert Denis, Bikram K. Mahajan, Avinash Kankipati, Dr. Xian Huang
Missouri University of Science and Technology
Mechanical and Aerospace Engineering Department
Epidermal electronic devices can be mounted directly on human or animal
skin like temporary tattoos, and have the potential to revolutionize health
and wellness monitoring techniques. These devices typically contain
elastomer membranes as backing layers to protect the electronic devices
from external scratching, while providing adhesion force to allow the
devices to stay on skin. However, the majority of the epidermal electronic
devices are attached to the skin using a releasing or transfer printing
process that involves the use of water soluble tape, which is inconvenient
and tedious to remove. Here, we develop an improved method using a
releasing film for the elastomer membranes and silicone adhesive for
better skin attachment. The releasing energy of individual interfaces of
these stacked layers (releasing film, oil film, elastomer membrane, and
silicone adhesive) were studied and measured using a tensile test
machine to determine the optimum combination of membrane materials
that will lead to easy membrane releasing on skin.
Additionally, a 3D printed micro needle array is used as a mold to
perforate the elastomer membrane to allow the water vapor from the skin
to escape, allowing the membrane to stay on skin for periods up to a
month.
• Find appropriate lubricant to facilitate the peeling of the releasing
tape.
• Design aesthetics for the releasing tape to ease the peeling.
• Design models to determine the peel force between the releasing
tape and the Dragon skin (with the lubricant), silicone adhesive and
the skin.
• Build the backing layers for practical tests.
• Composition of edible oil such as coconut oil and olive oil in a comparison
table
• Theory behind the peel force and the adhesion force
Rivlin equation states that:𝑭
𝒃=
𝑮
𝟏−𝒄𝒐𝒔𝜽
where F is the peel force, b the film width, G the adhesion energy, and θ the
peel angle between the film and the substrate.
• From the peel test we can conclude that the olive oil remains the best buffer.
• The chronological study of the membrane over the skin infers that the perforated
membrane stays over a longer time.
• Next, the peel force between a dummy skin and the silicone adhesive will be
determined so that the force between the adhesive and the skin remains bigger
than that of the force between the releasing tape and the silicon layer.
• The epidermal electronic device will then be embedded on the backing membrane
for health and wellness monitoring.
• The peel rate in all cases: 30 mm/min.
• The maximum peel force obtained for no oil, coconut oil, and olive oil samples,
is 15 N, 5.4 N, and 3.2 N respectively.
• The average load obtained for no oil, coconut oil, and olive oil is 10.097 N,
3.636 N, and 1.441 N respectively.
• Calculating the adhesion energy using rivlin equation at 1800in each case, we
get 448.76 J, 161.6 J, and 64.04 J respectively.
Elastomer Membrane
Elastomer membrane layers – side view
Oil typeViscosity
(poise)
Volume flow rate
(𝒄𝒎𝟑/sec)
Surface tension
(dyne/cm)
Coconut oil 0.229 7.76× 10−3 17.84
Olive oil 0.437 10.00× 10−3 10.00
Comparison table of two edible oils
• The use of Dragon skin series 10 slow(Silicone) and Silbione RT Gel
4317 A&B (Silicone adhesive).
Peel Test Model
Layers stacked in a petri dish
Aesthetics
Plain film
Cut film Diagonally cut film
Position vs Load graphs for samples with No Oil, Coconut oil and Olive Oil
60 mm
45
mm
ABSTRACT
0 20 40 60 80 100 120 1400.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Lo
ad
(N
)
Position(mm)
Olive Oil
0 20 40 60 80 1004
6
8
10
12
14
16
Lo
ad
(N
)
Position (mm)
No Oil
0 20 40 60 80
0
1
2
3
4
5
6
7
Lo
ad
(N
)
Position (mm)
Coconut Oil
Petri
Dish
Releasing
Film
This Research is supported by the National Science Foundation (NSF), Research
Experience for Undergraduates (REU) in Missouri S&T and the start-up funding from
Dr. Huang.
Releasing Tape Film
Electronic Device
Sweat Sensor RF Energy Harvester Hydration Sensor
Silicon Dioxide (Si𝑶𝟐)
Electronic Device
Silicon Dioxide (Si𝑶𝟐)
Silicone Layer
Water Soluble Tape
Epidermal device layers
Peel Test
Lower
clamp
Upper
clamp
Backing
layer
Releasing
film
1800 Peel test for a sample
under an UTM
Epidermal Electronic Devices
BACKGROUND
GOALS
PROCEDURES
CONCLUSION
ACKNOWLEDGEMENT
Lubricant Layer
Silicone Layer
Silicone Adhesive LayerTime
Elapsed
1 Hour view 2 Hour view 3 Hour view 4 Hour view 5 Hour view 6 Hour view 7 Hour view 8 Hour view
Membrane
Perforated
Membrane
Non
Perforated
• A chronological study has been done by placing both perforated and non-perforated
membranes on to the skin and observed for 8 hours.
• The membrane which has been perforated was observed to stay long on to the skin.
• The membrane which is not been perforated had the more tendency to loose the
adhesive due to the accumulation of sweat.
• We observed that the non-perforated edges have been rolled out after 8 hours.
Device backing membrane skin life span monitoring
3D micro needle array perforator
RESULTS & DISCUSSION