Low-pressure Bonding Technology And Its Mechanism Analysis

The fluid and molecular transport in micro/nano-channel have a specificnature of property and the related research already have some breakthrough whichdifferent from the traditional theory. Meanwhile, the micro/nano-channel hassignificant applications in biochemical. The fabrication of controlled polymermicro/nano-nanofluidic channels is a hot research spot in this field. Obviously,thermal bonding is the key technology to achieve sealed polymer channel. However,traditional bonding process require high temperature and high pressure，and it willeasily make the channel blocked up or cause geometric deformation. It will hinderthe development of wide applications.In this paper，a new method for the enclosure of the large-area channel bythermal bonding at low pressure was presented， which could avoid someshortcomings of traditional fabrication method. The entire manufacturing processas well as the key steps was given. Moreover, the fluid test experiment was carriedout. The experimental results explained that the method can produce a large area ofuniform micro/nano-channel.The mechanism of pressure-assisted capillary filling process was studied. Theeffect factors such as microscale effect, pressure, temperature, thickness of layerwere clarified. Finite element analysis software and VOF model was used tosimulate the low-pressure bonding and capillary force filling process, and thesimulation results coincide with the experimental results. At the same time, thetheoretical conditions for forming different shape of channel were given. Theseresults can well explain the polymer flow behavior and provide theoretical basis foroptimizing the roof filling process.Through the hypothesis of expansion center line, a filling barrier structure wasdesigned to reduce the displacement in the process of extrusion flow by pressure,which will play the function of diversion, thus inhibiting the appearing of channelblocked up. This low pressure bonding technique may enable laboratories withouthigh-end facilities to get involved in micro/nano-fluidics and its applications.