Smart gloves Building bricks Application scenarios ?
Keywords: - Multisensing/collaborative sensing - Flexible functional devices - Flex-rigid integration (hybrid) - Local communication (nanocom)
Jacek BABOROWSKI, MEMS Prototyping and Industrialization Microsystems Technology, CSEM Centre Suisse d'Electronique et de Microtechnique SA Neuchâtel, Switzerland
- Smart-gloves
Hermes Workshop Nano Communication and Technology for Autonomous, Ultra Miniature, Ultra Low Power, MultiFunctional Wireless Systems September 9th /10th , 2010, University of Lund, Sweden
Smart Gloves - outline
• Main idea • Piezoelectric resonating MEMS • Flexible substrates
Copyright 2010 CSEM | Smart Gloves | J.Baborowski | Page 1
Smart Gloves - Main idea • Smart gloves as generic term (more vision than well defined object) • The basic idea concerns smart gloves with integrated multisensing (e.g. touch, temperature and shear). • The primary target application is health (e.g. rehabilitation - something like the game WII – but made with smaller, multi- collaborative sensing devices). • Other applications are possible, though and could be discussed • smart gloves for providing tactility for very precise robots operating in harsh environments • smart gloves for intelligent control • smart gloves for security and safety applications • Highly miniaturized, integrated, ultra low power and dense body sensor networks which may be used for a variety of applications such as: •
to monitor and control conditions,
• administration of medications and perhaps augment capabilities (e.g. a kind of artificial skin to restore the sense of touch) • The initial focus is foreseen on the wearable – non-invasive
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Main idea... questions • What are the available sensors for “multisensing” ? • What could be the realistic applications, needs (what we get if we can obtain/improve sth…) • From fun (e.g.WII, see ST’s accelerometer) towards high-tech applications – really needed? • Don’t forget the physical laws! • In this talk: • Main idea/vision, fruit of the Hermes and CSEM brainstorming • Current developments (at CSEM, but not only) which fit or can be adapted to this vision • Fields in which we have a solid background and experience to defy / imagine new combinations/applications (e.g. integration of piezoelectric layer on polymers) • Piezoelectric resonant devices, robust stretchable electrodes
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Main idea... • Cross thematic subject : NMP & ICT • Fits to currently opened call: FP7/ NMP 2011.1.4-4 “Nanotechnology, based implantable and interfacable devices” •
“… Development of novel material platform for flexible devices with reduced biofouling to achieve
long-lasting operation without interface degradation and improved electro-chemical performance. Matching of the mechanical, electrical, and biological properties of implants with tissue characteristics. • Selective and multichannel electrodes or medical sensing devices with surfaces engineered at the nanoscale for optimal contact, combining electronic interfacing with anti-inflammatory and / or antibacterial functions; • Potential for spin-off applications such as smart gloves with integrated sensing and improved tactile transmission, for industrial hazardous, chemical, biological environments…”
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Hermes and CSEM brainstormings
Nanocommunication:
Multifunctional Sensing
Invasive
Nanorobots (Nawis): -Physical, - Antennas/ relays -Energy/waves? -Information only?
• • • •
Narrow range ULP 3D interactivity System aspects – sensor clusters
Noninvasive Micropatch
Smart-gloves
Powering: Multisensing & Collaborative sensing: • Gesture / tactile / motion / shock • Pressure / temperature • Collaborative sensing & communication
• Energy sources and power management • Energy harvesting and storage
Information exchange Biosafe electronic interfacing Security and interferences
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Building Blocks (FET NAWIS vision 2009)
Energy Harvesting
Antennas, rectennas and networking protocol
DEMO Modems and signal processing
Radio
LEVEL
Collaborative Harvesting
Prototype‐of‐Concept VISION Autonomous, intelligent nanorobots
IC
Energy
LEVEL
Main idea – Smart Gloves How to reach the goal ? To built the robust, flexible, multisensing / energy harvesting / RFcom = autonomous systems (idealistic)
Relying on • Piezoelectric MEMS with AlN actuation • Integrated on/into flexible substrates • Robust connectivity on flexible substrates
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Main idea - Smart Gloves • Available/needed technological bricks and competencies • Sensing: • Movement detection – inertial MEMS sensors (from the shell or innovative) • Piezoelectric resonators as temperature sensors / references • Piezoelectric sensors integrated on flexible substrates – tactile, pressure monitoring • Chemical – pH sensing, nano- functionalization • Energy sources: • Piezoelectric MEMS harvesters – resonating structures (IM EC/Holst, Imp.Col) • Other (body heat, light, pressure, flexible batteries e.g. Li-Po) – combination of all? • RF near range communication and connectivity: • MEMS based ULP radio • Flexible robust electrodes (local connectivity) • Packaging for harsh environment – robust, protective Copyright 2010 CSEM | Smart Gloves | J.Baborowski | Page 8
Smart Gloves exists !
www.imakproducts.com
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Piezoelectric AlN/Si MEMS devices • Silicon resonator with AlN activation (replacement of quartz) • Same technological platform as for BAW and some piezoelectric sensors or actuators: • Silicon as bulk material • SOI substrate for precise thickness • Bulk Si Micromachining • AlN piezoelectric thin film capacitor between metal electrodes (d31 - extension or flexion of beam/cantilever) AlN SiO2
SOI DEVICE SiO2
Si
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AlN based BAW Resonators (…GHz) Loading
•
SMR: Solidly-mounted Resonator
BAW filter
Loading layer
f
Electrodes
AlN Acoustic reflector Si wafer
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Piezoelectrically activated Silicon Low Frequency resonators from CSEM Inertial Si mass
Piezoelectric activation
Extensional mode: Fres = 1MHz Rm < 200 Ohm Q vac = 140 000 k2 < 0.1% FOM > 70 – 100 TCF : α = -28 +/-0.2 ppm/°C • Footprint: 4x3 mm2
Out-of-plane and In-Plane mode: Fres = 20 to 250 kHz Q vac up to 30000 k2 vac = 0.3% FOM= 30 to 90 1.5x1x0.5 mm2 TCF : α = 0 ppm/°C • Footprint: 2x1.5 mm2
• Currently used in MEMS ULP radio Copyright 2010 CSEM | Smart Gloves | J.Baborowski | Page 12
Smart Gloves – devices for sensing • Inertial – inertial MEMS sensors: • Rely and integrate the existing MEMS (e.g. ST-I gyro....bilion pieces/year) • Innovative-piezoelectric, tuning fork,... (sensitivity, linearity, no sticking, smaller)
• What else?
1mm
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Smart Gloves – devices for sensing • Piezoelectric resonators as temperature sensor (not pyroelectric !) • Thermal drift of resonance frequency as function of temperature • AlN/Si resonators (20kHz – 1MHz) • TFC -30 to 0 ppm/°C • Compensated TCF (calibration, electronic compensation, intrinsically) • 30ppm/°C at 100kHz:sensing electrode in contact with a body – 3Hz/°C of variation
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Smart Gloves – devices for sensing Piezoelectric sensors integrated on flexible substrates – non-invasive and unconstrained method has been proposed for measurement of respiration and heartbeat information during sleep •
Highly c-axis oriented AlN thin film can be deposited on flexible substrates, like aluminum foil, polyethylene terephthalate (PET), and polyimide films (Bu, 2009)
•
The total thickness of this sensor is less than 40 μm (imperceptible when integrated into a bed)
•
Good sensitivity - pressure fluctuation due to respiration and heartbeat can be measured
M. Akiyama et al., Flexible piezoelectric pressure sensors using oriented aluminum nitride thin films prepared on polyethylene terephthalate films, J. Appl. Phys., Vol. 100, Issue 11, 2006, Article No. 114318. M. Akiyama et al., Preparation of oriented aluminum nitride thin films on polyimide films and piezoelectric response with high thermal stability and flexibility, Adv. Func. Mater., Vol. 17, No. 3, 2007, pp. 458-462. Nan Bu et al., Respiration and Heartbeat Measurement for Sleep Monitoring Using a Flexible AlN Piezoelectric Film Sensor, Sensors & Transducers Journal, Vol. 110, Issue 11, November 2009, pp. 131-142 http://www.nanowerk.com/spotlight/spotid=17076.php
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Examples: • pressure fluctuation measured with a flexible AlN film sensor
• Examples of ECG signals (top) and the component of heartbeat xh(t) (bottom).
• Human pulse wave measurements (Akiyama et al.,) CSEM is strongly interested in the development of this kind of devices Copyright 2010 CSEM | Smart Gloves | J.Baborowski | Page 16
Smart Gloves – Chemical sensing • Important interfacing (outside/inside) aspects employing nanomaterials are proposed: • development and integration of sensors based on nanosensing layers • functional nanoporous sol-gel thin films or hydrogel as new interface for chemo / bio sensing (e.g. pH sensor, biosensor …), • functional nanoporous layer for drug release/encapsulation, • functional thin films (monolayer with nanoscale dimension) with specific properties e.g. antifouling.
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Piezoelectric MEMS for energy harvesting (IMEC/Holst) Existing energy harvesters tend to be fine machined, a costly method that can produce devices that generate power at levels from microwatts to watts.
MEMS devices are cheaper to produce, easier to integrate with existing sensors, and now they can generate enough power to run a wireless sensor node. • The smallest vibration-driven harvesters to date have mainly been realised on silicon using MEMS technology • IMEC have demonstrated an AlN/Si harvester with a volume of around 40 mm3 which has a resonant frequency of 500 Hz and can generate 85μW of output power.
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Piezoelectric MEMS for energy harvesting Downscaling of piezoelectric MEMS harvesters – resonating structures –further improvement needed: • Design optimisation? • Vacuum tight packaging • Power management? • Pre-biasing ! (Imp.College) • CSEM can bring: • piezoMEMS • packaging solutions
20-100kHz 1x2x2mm3
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Integration of piezoelectric MEMS & IC for miniaturization of ULP wireless sensor node • BulkAcousticWave resonators - to build RF LO and filters • Silicon Resonator - for stable FrequencyREF and RTC • Hybrid integration - Reduced volume 2x3x2 mm3 • Wafer-level packaging (vacuum/hermeticity sealing & proximity interconnects)
ESSCIRC PLENARY: D.Ruffieux et al.,, Ultra Low Power and Miniaturized MEMS-based Radio for BAN and WSN Applications Thursday Sep 16th, 2010 14h50-15h50
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Gloves as substrate - Flexible and stretchable robust electrodes • Metals deposited on polymers/ elastomers • Developed for “artificial muscles” (H.Shea et al.,) • CSEM develops currently a pneumatic/dielectric low-cost MEMS for tactile sensing (Electrostatic Pneumatic Hybrid (EPH) Concept for Braille display; EU project TACMON)
dot “1”
dot “0”
display
refresh
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Flexible and stretchable robust electrodes Implantation of metals in PDMS membranes Ion-implanted elastomer
Coated elastomer
100 nm Copyright 2010 CSEM | Smart Gloves | J.Baborowski | Page 22
Flexible and stretchable robust electrodes Implantation of Au in PDMS membranes
Implanted zone 3500 pulses
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Flexible and stretchable robust electrodes Implantation of Pt in PDMS membranes
Implanted Pt / PDMS: • Smooth and defectless surface • Resistance : < 80 Ohm • Deformation up to 200%, cycling
Undeformed
200x
Deformed
1000 x
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Au implanted in Latex - after stretching – 100% x 100 cycles
Resistivity (IDE) ~ 300 Ohm Copyright 2010 CSEM | Smart Gloves | J.Baborowski | Page 25
Hermes and CSEM brainstormings: Smart Gloves – sensing – energy - communication Nanocommunication:
Multifunctional Sensing
Invasive
Nanorobots (Nawys): -Physical, - Antennas/ relays -Energy/waves? -Information only?
• • • •
Narrow range ULP 3D interactivity System aspects – sensor clusters
Noninvasive Micropatch
Smart-gloves
Powering: Multisensing & Collaborative sensing: • Gesture / tactile / motion / shock • Collaborative sensing & communication • Dosing (?)
• Energy sources and power management • Energy harvesting and storage
Information exchange Biosafe electronic interfacing Security and interferences
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Smart Gloves – application scenario • Health and rehabilitation • Fine tactile devices/ precise handling • Security alarms (pH) • Screening (custom, airport security, drugs detection)
• Beyond Smart Gloves: • Aerospace
Discussion...
• Buildings
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Smart –gloves: Conclusions, discussion, questions • We need the sensors • We need the flexible substrates • We need to integrate all elements close to the body (human or other)
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Thank you for your attention!
