Carbon
MEMS
Fabrication of carbon structure through
pyrolysis of photoresist structure
: Dramatic size reduction up to ~90 %,
highly inert carbon electrode with fancy structure.
1. Electrochemical
sensor platform 1:1
aspect ratio IDA nanoelectrodes Batch fabrication of interdigitated
nanoelectrode array.
- Gap between electrode reduced down to 1.65 μm
1:1 aspect ratio (height: 340 nm, width:
300 nm) Redox cycling: High electrochemical signal
amplification
J. -I. Heo, D. S. Shim, G. Turon Teixidor, S. Oh, M. J.
Madou, H. Shin, , "Carbon Interdigitated Array Nanoelectrodes for
Electrochemical Applications," Journal of Electrochemcial Society 158, J76
(2011). Effect of microchannel height on redox
cycling effect of integrated interdigitated carbon nanoelectrode array.
- PDMS channel integration
- Current amplification up to 1116 times.
J. -I. Heo, Y. Lim, H. Shin, "Effect of channel height
and electrode aspect ratio on redox cycling at carbon interdigitated array
nanoelectrodes confined in a microchannel," Analyst 138, 6404 (2013).
Stacked carbon electrode set including a
suspended mesh made of nanowires and a substrate-bound planar electrode.
- Electrode gap reduced down to 2.1 μm
- Unit mesh size: 300–320-nm-wide and
560–600-nm-thick
- Redox current amplification(Ferrocyanide):
37 times
- Dopamine detection down to 5 μM
Y. Lim, J. I. Heo, H. Shin, “Fabrication and application of
a stacked carbon electrode set including a suspended mesh made of nanowires and
a substrate-bound planar electrode toward for an electrochemical/biosensor
platform,” Sensors and Actuators B 192, 796 (2014)
Selective immobilization of enzyme for
glucose sensor application. One of the IDA was selectively modified with GOx
via the electrochemical reduction of an aryl diazonium salt, while the other
comb remained unmodified. Increased active electrode surface resulted in better
performance.
- Electrode gap between two combs: 1.9 μm
- Sensitivity enhancement: ~2.3 times
- LOD enhancement: ~295 times
D. Sharma, Y. Lim, Y. Lee, H. Shin* , Glucose sensor based
on redox-cycling between selectively modified and unmodified combs of carbon
interdigitated array nanoelectrodes, Analytica Chimica Acta, in print.
Biosensor
platform: AuNP/C IDA nanoelectrodes Fabrication of an electrochemical-enzymatic
redox cycling-based cholesterol biosensor using 1:1 carbon interdigitated array
(IDA) nanoelectrodes decorated selectively with electrochemically deposited
gold nanoparticles (AuNPs).
- Nanoparticle size: 50~70 nm
- Sensitivity enhancement: 20~30 %
- LOD enhancement: 2~3 times
Suspended
single carbon nanowire as sensor platform
- Full utilization of high surface to volume ratio
No interference from the substrate
Y. Lim, J. I. Heo, M. J. Madou, H. Shin, “Monolithic carbon
structures including suspended single nanowires and nanomeshes,” Nanoscale
Research Letters 8, 492 (2013). Suspended single carbon nanowire functinalized with Pd thin film
- High hydrogen selectivity
- High sensitivity related to Pd material property
- Room temperature operation
Y. Lim, Y. Lee, J. I. Heo, H. Shin, “Highly sensitive hydrogen gas sensor based on a suspended palladium/carbon nanowire fabricated via batch microfabrication,” Sensors and Actuators B, 210, 218, (2015).
An array of suspended carbon nanowires functionalized Pd nanoparticles
- Controllable Pd nanoparticle morphology
- Wide sensing range according to array structure of nanowires
- High sensing performance according to self-heating effect
- Room temperature operation
Multiplex
gas sensor: Suspended MOx NWs ZnO nanowires were grown selectively on a
suspended single glassy carbon nanowire using hydrothermal method so that the
detrimental effects from the substrate inclusive of contamination, stagnant layer
and limited mass transfer could be alleviated.
- ZnO nanowire diameter: 30~80 nm
- ZnO nanowire length: 0.5~2 μm
 Carbonization of plasma etched polymer precursor
Patternable and controllable multiscale porous 3D carbon structures
- Large surface area & Electric conductivity : Supercapacitors, Sensors, etc.
- Polymer based batch process : Cost-effective
RTA-induced
conductivity enhancement Enhancing the electrical conductivity of
GC, so that it can compensate or be substituted for other carbon allotropes
such as graphite, carbon nanotubes, and graphene. After the RTA process, the
carbon/oxygen content and G-/D-band intensity ratios, which are correlated to
the electrical conductivity, were enhanced, depending on the pyrolysis
temperature.
- More ordered carbon phase via RTA
- Electrical conductivity enhancement: 3.3
times
5. Micro- and Nano mixed-scale channel networks
- Channel replication using a monolithic mixed-scale carbon mold
PDMS channel networks
- Simple fabrication of mixed-scale polyldimethylsiloxane (PDMS) channel networks via single molding process
- High throughput channel molding process
- Efficient single particle entrapment in Kingfisher-beak-shaped 3D microfunnel
Y. Lee, Y. Lim, H. Shin*, Mixed-scale channel networks
including Kingfisher-beak-shaped 3D microfunnels for efficient single particle
entrapment, Nanoscale 8 (2016) 11810-11817 (Front cover). http://pubs.rsc.org/is/content/articlehtml/2016/nr/c6nr00114a - Simple fabrication of mixed-scale polymethyl methacrylate(PMMA) channel networks via thermal nanoimprint method
- Repeated nanoimprint process owing to mechanically and chemically superb carbon mold.
- Smooth single particle entrapment via diffusiophoresis
SECM-AFM
Combination of atomic force microscopy(AFM) and scanning electrochemical microscopy(SECM) : Simultaneous scanning of topography and electrochemical data of sample surface Multifunctional Probe
Combined atomic force–scanning electrochemical microscopy
Scanning probe microscopes integrated with dual or single micro/nano electrode
- Simultaneous multiple surface data collection: topology, electrochemical data, pH, biological data, temperature, etc.
- Collection of biological data inside live cells
Conductive Material Nano-Printing
Localized electrochemical deposition of conductive materials using AFM probes
- AFM cantilever tip integrated with micro/nano electrode
- Continuous conductive material printing with high resolution
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