Printing Flexible Electronics for Health Care Applications

Printing Flexible Electronics
for health care Applications
Pit Teunissen
Eric Rubingh
Ruben Lelieveld
Marc Koetse
Juliane Gabel
Pim Groen
Printed and organic electronics
November 20, 2014

Presentation
overview
Printing Flexible Electronics for health care Applications, Pit Teunissen
1. Introduction smart blister
2. Device architecture
3. Way of working
4. Results
5. Towards high volume production
6. Conclusions
7. Outlook

© Holst Centre
Smart Blister
• Pharmaceutical package capable of monitoring when a pill is taken
out of its packaging
• Data can easily be transferred wireless via NFC
• Main purpose: To ensure that patients in clinical trials take their
medicine at the time and frequency recommended to avoid non-
compliance issues

© Holst Centre
Smart blister: Partner request
• Assembled
• “3D”-system
• High cost
• Added to existing package
• Fully integrated
• 2D-System in Foil
• Low cost, mass fabrication
• Roll to Roll compatible
Request from partner: from assembled
PCB to low-cost integrated system in foil

© Holst Centre
Technological challenges
System engineering
• Simplification, cost reduction
• Optimal chip set
• Design rules
Printing
• Conductivity (Antenna)
• Multi layer (circuitry)
• Overlay precision
Assembly
• Adhesives
• Accuracy
• Reliability and durability

Presentation
overview
1. Introduction Smart blister
2. Device architecture
3. Way of Working
4. results
5. Towards high volume production
6. Conclusions
7. Outlook

© Holst Centre
Substrate selection
Substrate:
• Price
 PI >50€/m2
 PEN <10 €/m2
 PET <1 €/m2
Preferred substrate  PET
• Tg PET ~ 100°C
 Processing temperature
< 130 °C

© Holst Centre
Building Blocks
sensing
logic
radio
antenna
power Thin film battery
Resistance ladder to monitor
which pill was taken from package
Integrated chips for measuring
and registration
Printed antenna for data transfer
Integrated chips for RFID
communication and data storage

© Holst Centre
Deposition method
Processing:
• High speed processing / large
volume
 R2R compatible
 High speed
 Resolution ~100µm features
 Multi-layer 100µm overlay
accuracy
 High aspect ratio for high
conductivity
Screen printing

© Holst Centre
Device layers
• Five layers
 1: Circuit including antenna
 ~100µm feature size
 Good conductivity
 2: Antenna
 ~100µm overlay accuracy
 ~100µm feature size
 Resistance ≤40 Ω
 3: Dielectric
 Good insulating properties
 Prevent shorts in crossing layers
 4: Bridges
 Make electrical contact between
components
 5: Printed resistors
 Monitor which pill is taken out
 Accurate resistance (< 5% deviation)

© Holst Centre
Components
Components
• 3 chip solution
 MC: micro controller (measure and register)
 RTC: real time clock (date, time)
 NFC Eeprom: RFID communication and data storage
• Thin components
 Components can be integrated in foil
• Assembly
 No soldering possible!
 Use novel low T cure isotropic conductive adhesives (100 °C cure)
without
package
thinning chip
down to 20-30 µm
chip becomes
flexible

© Holst Centre
Way of Working – Deposition method
• Screen printing: principle
 Paste is applied in a patterned mesh
 Mesh is positioned above substrate
 Ink is pushed through the mesh and
a direct image of the screen is made
on the substrate
smallest feature size
(lab)
30 m
(industrial scale)
80 m
ink viscosity range 100 – 800,000 mPas
wet layer thickness 12 – 500 m
dry layer thickness 0.5 – 50 µm
dry layer thickness
accuracy
15 – 40 %
alignment/overlay
accuracy
100 m
Processing time < 1 min. / sheet
Woven mesh

© Holst Centre
Way of working – Equipment and materials
• S2S screen printer
 DEK Horizon 03i
• Mesh technology
 Stainless steel woven mesh
 Stork Prints PlanoMesh, electroformed Nickel
• Materials
 Silver paste (layer 1, 2 and 4)
 1: Circuit, including antenna (DuPont 5025)
 2: Antenna (DuPont PV410)
 4: Bridges (DuPont 5025)
 Isolator (layer 3)
 3: Dielectric (DuPont 7165)
 Carbon (layer 5)
 5: Resistors (DuPont 7082 + DuPont 5036)
Stork Prints PlanoMesh
Dek screen printer

© Holst Centre
Way of working – Sintering
• Sintering
 Metal nano,- and micro particle need to be dried
and/or sintered to become conductive
 Sintering = merging particles via atomic diffusion
 Fraction of the bulk melting temperature
 Nanoparticle inks are ideal for conductive
structures on temperature-sensitive substrates
 Sintering can be done thermally, photonically,
electrically, using plasma, chemically, etc.
 Here we use thermal sintering in an oven at 130°C
Sintered Ag nanoparticles

© Holst Centre
Results
• 1st layer: circuit for electrical contacts
 Smallest line width: 100µm
 Good Conductivity
 Typical line height ~6µm
Profile measurement antenna Screen printed circuit

© Holst Centre
Results
• 2nd layer: antenna
 Extra layer is printed to improve the conductivity
 Resistance 15-16 Ohm (<40 Ohm needed)
 SPG PlanoMesh screens are used to print thicker in
one step while maintaining resolution
Stork Antenna DuPont 5025 + PV410
-5000
0
5000
10000
15000
20000
25000
30000
35000
40000
0 200 400 600 800 1000 1200 1400 1600 1800 2000
Position (µm)
Height(nm)
Profile measurement antenna
2 layers printed using woven mesh
Profile measurement antenna
2 layers printed using plano mesh

© Holst Centre
Results
• 3rd layer: dielectric
 Al spikes in Silver should be covered
 No pinholes allowed
Back scatter: White Silver; black dielectricLeft Silver; right Silver+dielectric
Defect piercing dielectric

© Holst Centre
Results
• 3rd layer: dielectric
 Depending on 1st layer, up to 4 layers needed to give optimal isolation
Pinhole in dielectric
Antenna silver lines
Cross section dielectric on Silver
Profile of antenna covered with dielectric

© Holst Centre
Results
• 4th layer: bridges
 Challenge is to print high resolution lines on multi layer stack
with >30µm step height
Printed 100µm lines on top of 2 layers of silver
and 4 layers of dielectric
Dielectric
Silver bridges
Profile of printed silver bridges on top of silver
and dielectric

© Holst Centre
Results
• 5th layer: printed resistors
• Results carbon resistors
 Resistance accuracy < 5% within one
sheet
 Practical tests show that with a resistance
ladder for 4 different pills pushed out all
combinations can be correctly registered
(DAC converter behavior)
 Low value resistors have larger resistance
than designed
 A theoretical model was made and showed the
same effect
 The edges of the large carbon resistors have a
relative larger contribution to the conductivity
compared with small carbon resistors

© Holst Centre
Results
• Towards lower cost materials
 Use printed copper for main circuit and bridges
 Antenna is still silver to get the high conductivity needed
 Working blisters were made
 160°C processing temperature needed
 Lifetime not yet good enough
Cross section Copper-dielectric-CopperSmart blister made of screen printed Copper

© Holst Centre
Results
• Current process suits for low volume production
 High volume needs continuous production process
4 intermediate generations
of smart blister
• Several working devices were made
Components on top Components in blister
Components in blisterComponents in blister
Final version of smart blister

© Holst Centre
Towards high volume production
Transfer from S2S process to R2R process
• Flatbed screen printing  Rotary screen printing
 Similar process as flatbed screen printing
 Circular formed mesh for continuous production
(lab)
40 m
(industrial scale)
100 m
ink viscosity range 100 – 80,000 mPas
wet layer thickness 12 – 500 m
dry layer thickness 500 – 50,000 nm
dry layer thickness
accuracy
15 – 40 %
alignment/overlay
accuracy
100 m
linear line speed >> 10 m/min, independent
from resolution

© Holst Centre
Towards high volume production
Transfer from S2S process to R2R process
• Thermal sintering  Photonic sintering
 Selective heating through light absorption by the ink, not by
the foil
 High energy densities achieved by light focusing with an
elliptical reflector
 Pulsed light instead of continuous radiation to prevent
excessive heating and substrate deformation Reflector geometry
Fast sintering (50 ms) of
development paste
3 flashes of 10 ms
Ref: Abbel et al., MRS Commun., 2012, 2, 145.

© Holst Centre
• Inline temperature and resistance measurement
 The temperature profile reveals the change in material properties of the
conductive ink. DuPont W693 (Ag development paste) on PEN
Photonic Sintering: Process study
Thermal conductivity: Low
Heat capacity: High
Thermal conductivity: High
Heat capacity: Low
Tg of PEN

© Holst Centre
• Entrapped solvents, bubbles and ablation
 Top illumination: Shell formation
 Short pulses: Not suited for drying
 Fast heating: Entrapped solvents and exploding bubbles
 Solvent evaporation: Back illumination and long pulses
 High peak temperatures: Ablation due to polymer degradation
Process study
Shell formation
Short pulses
Ablation (pre-dried ink)
High peak temperature
Exploding bubbles
Fast heating
50 x 50 xSEM, 100 x

© Holst Centre
• Sequence flash sintering (Silver np ink)
 To achieve highly conductive structures without deforming the
temperature-sensitive substrate, two flash settings are used
Process Time Temperature Pulse settings
Solvent evaporation seconds < Tg low intensity, high frequency
Sintering milliseconds >(>) 250°C high intensity, short pulse(s)
 Using NIR pre-drying is a good alternative for the first stage
50x
Photonic sintering – process study

© Holst Centre
• Stand alone photonic sintering unit
 Research tool to investigate sintering behavior
of conductive inks
 Elliptic shaped reflector to focus light
 Inline resistance and temperature
measurement (4-point)
 Nitrogen atmosphere possible (copper inks)
• S2S photonic sintering unit
 Research tool to upscale from single line to
30x30 cm
 2 side illumination
 Up to 10 lamps
 Inline resistance and temp.
measurement (4-point)
Photonic sintering: Experimental setup (1)
Stand alone photonic sintering unit

© Holst Centre
Pit Teunissen, The IJC Dusseldorf, September 30, 2014
< 33
Novacentrix PulseForge 1300
 Max radiant energy delivered
 45 (J/cm2)
 Curing dimension per pulse
 75 x 150 (mm)
 Max area cured per sample
 300 x 150 (mm)
 Capable of sintering copper materials
 Particle based, complexes, oxides
Additional functionality developed at Holst
 Inline measurement at 10,000 samples/s
 Resistance
 Temperature
 Functionalities beyond sintering only
Photonic sintering: Experimental setup (2)

© Holst Centre
Rotary screen printing of functional structures: 3 layer stack
 1st layer: Circuitry
 2nd layer: Isolation
 3rd layer: Bridges
Photograph of the R2R system containing the rotary screen printer and the sintering module
R2R rotary screen printing and in-line photonic sintering

© Holst Centre
Conclusions
• Screen printing was demonstrated as a cheap manufacturing method for
smart blisters
 5 different layers were printed
 Good conductivity
 Overlay accuracy of ~100µm; even on multi-layer stack
 Printed resistance ladders to monitor which pill is removed
 Thinned down components integrated in foil
• Rotary screen printing in combination with NIR drying and photonic
sintering was shown to be a way for high volume production

© Holst Centre
Roll to roll inkjet printing
 Printer: SPG inkjet printer
 Print head: Xaar 1001
 Material: Sun Chemical EMD5603
 Foil: Agfa PET, 125 µm
 Print speed: 10 m/min
Outlook processing
Movie: R2R Inkjet printing and sintering
Sintering module
 NIR dryer
 60% Power
 Photonic sintering
 2 lamps used;10Hz, 60% intensity

© Holst Centre
System in foil solution
Tutorial Hybrid Electronics – LOPEC 2014 (Munich) 26/05/2014
Storeskin
• shelve can detect spatially
resolved presence of objects
• done by integration of a
‘large area pressure sensing foil’
• Only digital signals to outside
world: more reliable

© Holst Centre
Skinpatch
• Wearable health application
• Demonstrated to work with
monitoring skin temperature,
humidity and movement

© Holst Centre
User interface design conference, April 1, 2014
Health patch
• Screen printed electrodes
• Disposable patch, reuse of electronics
• Stretchable electrodes for comfort

© Holst Centre
User interface design conference, April 1, 2014
Multi-functional printed sensor
• Sweat sensor
• Sensor measures ions (sodium, chloride);
measure for dehydration
• More functionalities are under development

Pain relieve bandage
• For RSI patients
• Wearable electronics
• Stretchable and conformable printed circuit
• Integrated LED’s

© Holst Centre
Outlook application
Storeskin
• shelve can detect spatially resolved
presence of objects
• done by integration of a
‘large area pressure sensing foil’
• electronics external, hidden in box
• Luxury chocolate box with
integrated light sensor and
LED’s
• Upon opening the box, the light
sensor activates the LED’s
• LED’s reveal location of origin of
the chocolate
local printing company started doing explorative
work on printed electronics after attending several
workshops on this topic by Holst Centre and TNO

Printing Flexible Electronics for Health Care Applications

Empfohlen

Empfohlen

Weitere ähnliche Inhalte

Was ist angesagt?

Was ist angesagt? (20)

Andere mochten auch

Andere mochten auch (15)

Ähnlich wie Printing Flexible Electronics for Health Care Applications

Ähnlich wie Printing Flexible Electronics for Health Care Applications (20)

Printing Flexible Electronics for Health Care Applications