PMID- 19331420
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20090702
LR  - 20200930
IS  - 1530-6992 (Electronic)
IS  - 1530-6984 (Linking)
VI  - 9
IP  - 5
DP  - 2009 May
TI  - Probing flow velocity with silicon nanowire sensors.
PG  - 1984-8
LID - 10.1021/nl900238a [doi]
AB  - We report our experimental efforts to quantify the impact of fluidic and ionic 
      transport on the conductance level of silicon nanowire (SiNW) sensors configured 
      as field effect transistors (FETs). Specifically, the conductance of SiNW FETs 
      placed in a microfluidic channel was observed to change linearly with the flow 
      velocity of electrolytic solutions. The direction of conductance change depends 
      on the doping type of the SiNWs and their location inside the microfluidic 
      channel, and the magnitude of the conductance change varies with the ionic 
      strength and compositions of the electrolytic solution. Our quantitative analysis 
      suggests that the flow velocity sensing is a consequence of the streaming 
      potential that is generated by the movement of counterions inside the electrical 
      double layer (EDL) of the silica substrate. The streaming potential, which varies 
      with the flow velocity and the ionic properties of the electrolytic solution, 
      acts in the same way as the charged analytes in affecting the conductance of 
      SiNWs by changing the surface potential. This study highlights the importance of 
      considering the ionic transport in analyzing and optimizing nanowire FET sensors, 
      which can significantly change the conductance of NWs. Moreover, SiNWs were 
      demonstrated for the first time to be able to detect the streaming potential, the 
      flow velocity and the ionic strength, opening up their new application potentials 
      in microfluidics.
FAU - Kim, Dong Rip
AU  - Kim DR
AD  - Department of Mechanical Engineering, Stanford University, California 94305, USA.
FAU - Lee, Chi Hwan
AU  - Lee CH
FAU - Zheng, Xiaolin
AU  - Zheng X
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - Nano Lett
JT  - Nano letters
JID - 101088070
EDAT- 2009/04/01 09:00
MHDA- 2009/04/01 09:01
CRDT- 2009/04/01 09:00
PHST- 2009/04/01 09:00 [entrez]
PHST- 2009/04/01 09:00 [pubmed]
PHST- 2009/04/01 09:01 [medline]
AID - 10.1021/nl900238a [doi]
PST - ppublish
SO  - Nano Lett. 2009 May;9(5):1984-8. doi: 10.1021/nl900238a.