PMID- 31057852
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20200930
IS  - 2055-7434 (Electronic)
IS  - 2096-1030 (Print)
IS  - 2055-7434 (Linking)
VI  - 3
DP  - 2017
TI  - Fabrication of all-transparent polymer-based and encapsulated nanofluidic devices 
      using nano-indentation lithography.
PG  - 16084
LID - 10.1038/micronano.2016.84 [doi]
LID - 16084
AB  - In this paper, we describe a novel and simple process for the fabrication of 
      all-transparent and encapsulated polymeric nanofluidic devices using 
      nano-indentation lithography. First, a nanomechanical probe is used to 'scratch' 
      nanoscale channels on polymethylmethacrylate (PMMA) substrates with sufficiently 
      high hardness. Next, polydimethylsiloxane (PDMS) is used twice to duplicate the 
      nanochannels onto PDMS substrates from the 'nano-scratched' PMMA substrates. A 
      number of experiments are conducted to explore the relationships between the 
      nano-indentation parameters and the nanochannel dimensions and to control the 
      aspect ratio of the fabricated nanochannels. In addition, traditional 
      photolithography combined with soft lithography is employed to fabricate 
      microchannels on another PDMS 'cap' substrate. After manually aligning the 
      substrates, all uncovered channels on two separate PDMS substrates are bonded to 
      achieve a sealed and transparent nanofluidic device, which makes the dimensional 
      transition from microscale to nanoscale feasible. The smallest dimensions of the 
      achievable nanochannels that we have demonstrated thus far are of ~20 nm depth 
      and ~800 nm width, with lengths extendable beyond 100 mum. Fluid flow experiments 
      are performed to verify the reliability of the device. Two types of colloidal 
      solution are used to visualize the fluid flow through the nanochannels, that is, 
      ethanol is mixed with gold colloid or fluorescent dye (fluorescein 
      isothiocyanate), and the flow rate and filling time of liquid in the nanochannels 
      are estimated based on time-lapsed image data. The simplicity of the fabrication 
      process, bio-compatibility of the polymer substrates, and optical transparency of 
      the nanochannels for flow visualization are key characteristics of this approach 
      that will be very useful for nanofluidic and biomolecular research applications 
      in the future.
FAU - Wu, Cong
AU  - Wu C
AD  - Department of Mechanical and Biomedical Engineering, City University of Hong 
      Kong, Hong Kong 999077, China.
FAU - Lin, Tiffany G
AU  - Lin TG
AD  - Department of Biomedical Engineering, University of California, Irvine, CA 
      92697-2715, USA.
FAU - Zhan, Zhikun
AU  - Zhan Z
AD  - Department of Automation, Yanshan University, Qinghuangdao 066004, China.
FAU - Li, Yi
AU  - Li Y
AD  - Department of Mechanical and Biomedical Engineering, City University of Hong 
      Kong, Hong Kong 999077, China.
FAU - Tung, Steve C H
AU  - Tung SCH
AD  - Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 
      72701, USA.
FAU - Tang, William C
AU  - Tang WC
AD  - Department of Biomedical Engineering, University of California, Irvine, CA 
      92697-2715, USA.
FAU - Li, Wen J
AU  - Li WJ
AD  - Department of Mechanical and Biomedical Engineering, City University of Hong 
      Kong, Hong Kong 999077, China.
LA  - eng
PT  - Journal Article
DEP - 20170327
PL  - England
TA  - Microsyst Nanoeng
JT  - Microsystems & nanoengineering
JID - 101695458
PMC - PMC6445022
OTO - NOTNLM
OT  - indentation lithography
OT  - nanochannel
OT  - nanofluidic device
OT  - nanofluidic flow
COIS- The authors declare no conflict of interest.
EDAT- 2017/03/27 00:00
MHDA- 2017/03/27 00:01
PMCR- 2017/03/27
CRDT- 2019/05/07 06:00
PHST- 2016/06/01 00:00 [received]
PHST- 2016/10/03 00:00 [revised]
PHST- 2016/10/10 00:00 [accepted]
PHST- 2019/05/07 06:00 [entrez]
PHST- 2017/03/27 00:00 [pubmed]
PHST- 2017/03/27 00:01 [medline]
PHST- 2017/03/27 00:00 [pmc-release]
AID - micronano201684 [pii]
AID - 10.1038/micronano.2016.84 [doi]
PST - epublish
SO  - Microsyst Nanoeng. 2017 Mar 27;3:16084. doi: 10.1038/micronano.2016.84. 
      eCollection 2017.