SLIDE 1
May 14, 2014 Wireless Physiology Webinars
Outline
- Research Background and Device Design
- Surface EMG-based Human-Machine Interfaces
- EEG-based Brain-Computer Interfaces
May 14, 2014 Wireless Physiology Webinars Outline Research - - PowerPoint PPT Presentation
May 14, 2014 Wireless Physiology Webinars Outline Research - - PowerPoint PPT Presentation
May 14, 2014 Wireless Physiology Webinars Outline Research Background and Device Design Surface EMG-based Human-Machine Interfaces EEG-based Brain-Computer Interfaces Research Background Current Future? Past Industrial
SLIDE 2
SLIDE 3
Industrial Personal Past Current
PNAS 106, 10875 (2009). Science 327, 1603 (2010).
Future? Bio-Integr. / Bio-Insp.
Research Background
SLIDE 4
Research Background
Soft Material based Stretchable Electronics
??
Bio-integration with Si electronics?
SLIDE 5
Research Background
Non-invasive monitoring of electrophysiological signals
Mechanical mismatch (modulus) Skin irritation/allergy (gel) Uncomfortable (stiff and heavy)
SLIDE 6
Our Method
Science 333, 838 (2011)
Ultra-thin, Lightweight, Stretchable electronics system on skin “Epidermal Electronics System (EES)”
SLIDE 7
Mechanics and Materials
Finite Element Method (FEM): parametric study of various filamentary serpentine (FS)-based, open mesh structures
√ √
30% strains
FEM estimates the mechanical stability upon stretching and bending
- Max. prin. strain < materials’ fracture strain (1 %)
x
30% strains more surface contact
SLIDE 8
Mechanics and Materials
R=45µm, w=20µm, t=200nm Gold in polyimide (PI)
YEO, Advanced Materials, 6837, 2013
SLIDE 9
Mechanics and Materials
Fabrication?
Schematics of fabrication
- r elastomeric stamp
Side view of fabrication process
- r elastomeric stamp
- r on the skin
SLIDE 10
Movie) printing of stamp-mounted EES to the skin
SLIDE 11
SLIDE 12
Mechanics and Materials
THICKNESS of EES for conformal and intimate contact?
*Local deformation energy at EES edges are negligible. Skin is regarded as a semi-infinite body
Conformal contact: when the adhesion energy is bigger than the sum of the EES bending and skin elastic energy.
YEO, Advanced Materials, 6837, 2013
SLIDE 13
Mechanics and Materials
Critical thickness≈25µm when amplitude is 100µm* and wavelength is 140µm** (max values)
*Tchvialeva, InTech, 2010, **Schwindt, Acta. Derm. Venereol, 1998
SLIDE 14
Mechanics and Materials
Scanning electron microscopy (tilted and x-sectional view)
√
YEO, Advanced Materials, 6837, 2013
SLIDE 15
SLIDE 16
Surface EMG-based Human-Machine Interfaces
SLIDE 17
Materials and Characterization
YEO, Advanced Materials, 2773, 2013
Design optimization of EES for surface EMG recording on forearm Bar-type electrode Circle-type electrode
SLIDE 18
Materials and Characterization
YEO, Advanced Materials, 2773, 2013
surface EMG on forearm by muscle flexion
SLIDE 19
Materials and Characterization
YEO, Advanced Materials, 2773, 2013
Data acquisition with BioCaptureTM, Great Lakes Neurotechnologies
SLIDE 20
Movie) sEMG recording with EES on forearm
SLIDE 21
Materials and Characterization
1) Inter-electrode spacing? 20 mm
flexor extensor
SLIDE 22
Materials and Characterization
YEO, Advanced Materials, 2773, 2013
2) Membrane thickness and 3) Device type? 5µm in thickness Bar 1
A ≈ conformal contact
SLIDE 23
Materials and Characterization
EES vs conventional? (signal and motion artifact)
1 2 3 4 5
- 0.2
- 0.1
0.0 0.1 0.2 Amplitude (mV) Time (sec) Conventional Epidermal
SLIDE 24
Human-Machine Interfaces via EES
sEMG for quadrotor control Rotation: ‘take off’ and ‘land’, Left: ‘clockwise rotation’, Right: ‘counter-clockwise rotation’, Squeeze: ‘fly forward’
SLIDE 25
Movie of quadrotor control
SLIDE 26
EEG-based Brain-Computer Interfaces
SLIDE 27
Unpublished data
SLIDE 28
Summary
Materials and mechanics for epidermal electornics sEMG and EEG electrodes and applications for human-machine interfaces
Smart Healthcare System
SLIDE 29