Fabrication and flow test of long-term hydrophilic fluidic chip without using any surface modification treatment

Abstract

In order to effectively pump liquid in a fluidic chip, the PDMS or SU8 channels were frequently modified by surface treatments to obtain the hydrophilic surface but encountered the problem of the hydrophobic recovery. In this article, long-term highly hydrophilic fluidic chips were demonstrated using rapid fabrication of low-power CO 2 laser ablation and low-temperature glass bonding with an interlayer of liquid crystal polymer (LCP). The intrinsic hydrophilic materials of glass and LCP were beneficial for self-driven flow in the long-term fluidic chip by surfacetension force with no extra fluidic pumps. The higher viscosity fluid could increase the difficulty of self-driven capability. The stability of contact angle and flow test of the chip after 2 months is similar to that at beginning. The high-viscosity human whole blood was successfully driven at an average moving velocity of about 1.89 mm/s for the beginning and at 2.04 mm/s after 2 months. Our fluidic chip simplifies the traditional complex fabrication procedure of glass chips and conquers the problem of traditional hydrophobic recovery.

Highly efficient Suzuki cross-coupling reaction within an open channel plastic microreactor immobilized with palladium complexes

“…In addition, the contact angle decreased by another 10°after introduction of Pd(OAc) 2 . It is reported that the lower the contact angle, the higher the driving force (Chung et al 2009) for the flow inside a microchannel. Low contact angles of modified COC materials might be favorable for long-term self-driving of aqueous solution inside the channel.…”

Simultaneous metering and dispensing of multiple reagents on a passively controlled microdevice solely by finger pressing

“…Laser ablation-based micromachining is gathering increasing attention because of its markedly faster prototyping speed, lower labor cost and higher level of automation. [26][27][28][29] The conditions for laser ablation of PDMS have been previously discussed by Liu et al 29 and Forgarty et al 30 In brief, features in the PDMS layer were designed using CorelDraw 10.0 and then engraved using VersaLaser VLS 3.50 with a 50 W CO 2 laser source (Universal Laser System Inc.) into either a 290 μm (for diode and metering chamber) or a 1.5 mm (for finger pump) thick commercial PDMS film (Rogers Corp.). The diode flap was formed by partially ablating the PDMS film, and the metering chambers were created by complete through-cutting in the same film (ESI, † section 1).…”

Rapid glucose concentration detection utilizing disposable integrated microfluidic chip

“…The results showed that a mixing performance of up to 90% could be obtained; even at low Reynolds numbers. CO 2 laser machining systems provide a low-cost and flexible means of patterning high-aspect microchannels on glass and polymer-based substrates (Yuan and Das 2007;Chung et al 2009Chung et al , 2010Huang et al 2009;Hong et al 2010;Yeh et al 2010). In developing a microfluidic chip for concentration detection applications, Klank et al (2002) showed that the characteristic Gaussian-like crosssection of the ablated microchannel was beneficial in aligning the optical fibers inserted into the chip following the bonding process.…”