Determination of wettability of surface‐modified hot‐embossed polycarbonate wafers used in microfluidic device fabrication via XPS and ToF‐SIMS

Baytekin, H. Tarık; Wirth, Thomas; Groß, Thomas; Treu, Dieter; Sahre, Mario; Theisen, Janko; Schmidt, Martin; Unger, Wolfgang

doi:10.1002/sia.2724

Cited by 17 publications

(18 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus an indirect approach for predicting contact angle is of direct benefit to industries where wettability is crucial but contact angle measurements cannot be directly acquired. To overcome this limitation, Baytekin et al [2] have demonstrated the use of surface analytical methods such as time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy to study points of interest in microfluidic devices and provide information on the surface chemistry established there. By using flat reference polymer wafers made from the same material, where the contact angle can be measured as usual, appropriate calibration curves can be established.…”

Section: Introductionmentioning

confidence: 99%

Predicting the wettability of patterned ITO surface using ToF‐SIMS images

Shard

Lee

et al. 2010

Surface & Interface Analysis

View full text Add to dashboard Cite

Partial least squares (PLS) regression has been increasingly used as a tool for modelling linear relations between multivariate surface analytical measurements and measures of performance. However, the use of PLS to obtain quantitative predictions has only been partially explored. In this study, we construct a PLS model using time-of-flight secondary ion mass spectrometry (ToF-SIMS) and water contact angle (WCA) data obtained from a series of differently treated indium tin oxide (ITO) surfaces. This model displays a reasonable correlation between the WCA values and the SIMS data. To validate the model, ITO surfaces patterned with different areas of wettability were examined using ToF-SIMS imaging to produce WCA maps. The PLS model was applied to predict the spatial variation in WCA across the sample. The direct measurement of WCA on the patterned ITO surface was achieved using a small-scale interval grid from picolitre volume water droplets. We present the correlations between the predicted WCA from SIMS and the measured WCA, and highlight the discrepancies that arises in the comparison of the two datasets. This work is of direct benefit to industries where wettability is crucial but direct contact angle measurements are acquired on a scale smaller than it is possible to produce liquid drops, such as the plastic electronics and microfluidics industries.

show abstract

Section: Introductionmentioning

confidence: 99%

Predicting the wettability of patterned ITO surface using ToF‐SIMS images

Shard

Lee

et al. 2010

Surface & Interface Analysis

View full text Add to dashboard Cite

show abstract

“…X-ray Photoelectron Spectroscopy (XPS) measurements reveal that oxygen content on the surface is increased, carbon content is depleted while oxygen functional groups are formed such as carbonyl (-C=O), carboxyl (-COOH) and carbonate (CO 3 ) [21,[26][27][28]. The appearance of functional groups increases the surface free energy of the material.…”

Section: Resultsmentioning

confidence: 99%

Long-lasting FR-4 surface hydrophilisation towards commercial PCB passive microfluidics

Vasilakis

Moschou

Carta

et al. 2016

Applied Surface Science

View full text Add to dashboard Cite

Highlights oxygen plasma treatment on FR-4 laminates  effect of power and exposure time studied to achieve long-lasting hydrophilic properties  super-hydrophilic surface for 13 days demonstrated  surface remains weakly hydrophilic between 13 th and 26 th day after the treatment  hydrophilic behaviour is retained for 26 days in total  oxygen plasma treatment was used on a commercially manufactured PCB microfluidic chip to enable passive filling of a microfluidic network AbstractPrinted circuit boards (PCB) technologies are an attractive system for simple sensing and microfluidic systems. Controlling the surface properties of PCB material is an important part of this technology and to date there has been no study on long-term hydrophilisation stability of these materials. In this work, the effect of different oxygen plasma input power and treatment duration times on the wetting properties of FR-4 surfaces was investigated by sessile droplet contact angle measurements. Super and weakly hydrophilic behaviour was achieved and the retention time of these properties was studied, with the hydrophilic nature being retained for at least 26 days. To demonstrate the applicability of this treatment method, a commercially manufactured microfluidic structure made from a multilayer PCB (3-layer FR-4 stack) was exposed to oxygen plasma at the optimum conditions. The structures could be filled with deionised (DI) water under capillary flow unlike the virgin devices.

show abstract

“…In general, these polymers are hydrophobic in nature and the control of the wettability requires additional surface treatments. The surface modification techniques employed up to now in hot-embossed polymers typically resort either to plasma treatments [41,42] or to the formation of self-assembled monolayers (SAMs) [43]. However, such treatments have been demonstrated to have a limited lifetime.…”

Section: Introductionmentioning

confidence: 99%