PMID- 31775220
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20200928
IS  - 2079-4991 (Print)
IS  - 2079-4991 (Electronic)
IS  - 2079-4991 (Linking)
VI  - 9
IP  - 12
DP  - 2019 Nov 25
TI  - Increased Flexibility in Lab-on-Chip Design with a Polymer Patchwork Approach.
LID - 10.3390/nano9121678 [doi]
LID - 1678
AB  - Nanofluidic structures are often the key element of many lab-on-chips for 
      biomedical and environmental applications. The demand for these devices to be 
      able to perform increasingly complex tasks triggers a request for increasing the 
      performance of the fabrication methods. Soft lithography and 
      poly(dimethylsiloxane) (PDMS) have since long been the basic ingredients for 
      producing low-cost, biocompatible and flexible devices, replicating 
      nanostructured masters. However, when the desired functionalities require the 
      fabrication of shallow channels, the "roof collapse" phenomenon, that can occur 
      when sealing the replica, can impair the device functionalities. In this study, 
      we demonstrate that a "focused drop-casting" of h-PDMS (hard PDMS) on 
      nanostructured regions, provides the necessary stiffness to avoid roof collapse, 
      without increasing the probability of deep cracks formation, a drawback that 
      shows up in the peel-off step, when h-PDMS is used all over the device area. With 
      this new approach, we efficiently fabricate working devices with reproducible 
      sub-100 nm structures. We verify the absence of roof collapse and deep cracks by 
      optical microscopy and, in order to assess the advantages that are introduced by 
      the proposed technique, the acquired images are compared with those of cracked 
      devices, whose top layer, of h-PDMS, and with those of collapsed devices, made of 
      standard PDMS. The geometry of the critical regions is studied by atomic force 
      microscopy of their resin casts. The electrical resistance of the nanochannels is 
      measured and shown to be compatible with the estimates that can be obtained from 
      the geometry. The simplicity of the method and its reliability make it suitable 
      for increasing the fabrication yield and reducing the costs of nanofluidic 
      polymeric lab-on-chips.
FAU - Pezzuoli, Denise
AU  - Pezzuoli D
AD  - Department of Physics, Universita degli Studi di Genova, Via Dodecaneso 33, 16146 
      Genova, Italy.
FAU - Angeli, Elena
AU  - Angeli E
AUID- ORCID: 0000-0003-4774-2223
AD  - Department of Physics, Universita degli Studi di Genova, Via Dodecaneso 33, 16146 
      Genova, Italy.
FAU - Repetto, Diego
AU  - Repetto D
AD  - Department of Physics, Universita degli Studi di Genova, Via Dodecaneso 33, 16146 
      Genova, Italy.
FAU - Guida, Patrizia
AU  - Guida P
AD  - Department of Physics, Universita degli Studi di Genova, Via Dodecaneso 33, 16146 
      Genova, Italy.
FAU - Firpo, Giuseppe
AU  - Firpo G
AD  - Department of Physics, Universita degli Studi di Genova, Via Dodecaneso 33, 16146 
      Genova, Italy.
FAU - Repetto, Luca
AU  - Repetto L
AD  - Department of Physics, Universita degli Studi di Genova, Via Dodecaneso 33, 16146 
      Genova, Italy.
LA  - eng
PT  - Journal Article
DEP - 20191125
PL  - Switzerland
TA  - Nanomaterials (Basel)
JT  - Nanomaterials (Basel, Switzerland)
JID - 101610216
PMC - PMC6955689
OTO - NOTNLM
OT  - nanochannel
OT  - nanofabrication
OT  - nanofluidic device
OT  - polydimethylsiloxane
OT  - polymeric device
COIS- The authors declare no conflict of interest.
EDAT- 2019/11/30 06:00
MHDA- 2019/11/30 06:01
PMCR- 2019/11/25
CRDT- 2019/11/29 06:00
PHST- 2019/10/25 00:00 [received]
PHST- 2019/11/19 00:00 [revised]
PHST- 2019/11/20 00:00 [accepted]
PHST- 2019/11/29 06:00 [entrez]
PHST- 2019/11/30 06:00 [pubmed]
PHST- 2019/11/30 06:01 [medline]
PHST- 2019/11/25 00:00 [pmc-release]
AID - nano9121678 [pii]
AID - nanomaterials-09-01678 [pii]
AID - 10.3390/nano9121678 [doi]
PST - epublish
SO  - Nanomaterials (Basel). 2019 Nov 25;9(12):1678. doi: 10.3390/nano9121678.