Sacrificial adhesive bonding: a powerful method for fabrication of glass microchips

Abstract

A new protocol for fabrication of glass microchips is addressed in this research paper. Initially, the method involves the use of an uncured SU-8 intermediate to seal two glass slides irreversibly as in conventional adhesive bonding-based approaches. Subsequently, an additional step removes the adhesive layer from the channels. This step relies on a selective development to remove the SU-8 only inside the microchannel, generating glass-like surface properties as demonstrated by specific tests. Named sacrificial adhesive layer (SAB), the protocol meets the requirements of an ideal microfabrication technique such as throughput, relatively low cost, feasibility for ultra large-scale integration (ULSI), and high adhesion strength, supporting pressures on the order of 5 MPa. Furthermore, SAB eliminates the use of high temperature, pressure, or potential, enabling the deposition of thin films for electrical or electrochemical experiments. Finally, the SAB protocol is an improvement on SU-8-based bondings described in the literature. Aspects such as substrate/resist adherence, formation of bubbles, and thermal stress were effectively solved by using simple and inexpensive alternatives.

Microfluidics Based Point‐of‐Care Diagnostics

“…This new technique relies on the conventional method of bonding two glass slides irreversibly with an additional step of removing the SU‐8 from the microchannels only. Further, this method offers many advantages such as low cost, the feasibility of ultra large scale integration, overcoming the challenges of material adherence, removal of bubbles with great adhesion strength (Figure (ii)) …”

“…Glass slide (a), deposition of SU‐8 over this wafer and then pre‐bake (b), preliminary bonding against the glass substrate with the walls of the microchannel coated with a thin film of Al (golden in the drawings) (c), cure of the resist just around the microchannel after UV exposure and PEB (resist under the channel is not cured because it is protected from UV by thin film of Al that is deposited only inside the microchannel) (d), removal of the uncured SU‐8 and, next, of the Al film by pumping specific solvents (blue in the drawing) (e), and final chip showing residual SU‐8 in the bottom of the sidewalls (f). Reproduced with permission . Copyright 2015, Macmillan Publishers Limited, part of Springer Nature.…”

Microemulsification-based method: analysis of ethanol in fermentation broth of sugar cane

“…MEC stands out in relation to the others when considering parameters of wide linearity and low cost. 23 Apart from this feature, the cost of MEC-based kits for chemical measurements would be signicantly low because only the consumables would affect such a cost.…”

Mechanical, dielectric, and thermal properties of polydimethylsiloxane/polysilsesquioxane nanocomposite for sealant application

“…The silicone sealants are usually consist of hydroxyl‐terminated polydimethylsiloxane (PDMS), fillers, crosslinking agents, and other ingredients such as adhesion promoting agents . They are widely used in construction . The strength of the adhesive joint of silicone sealants depends on their cohesive and mechanical interlocking properties.…”