‘Fab-Chips’: a versatile, fabric-based platform for low-cost, rapid and multiplexed diagnostics

Abstract

Low cost and scalable manufacture of lab-on-chip devices for applications such as point-of-care testing is an urgent need. Weaving is presented as a unified, scalable and low-cost platform for the manufacture of fabric chips that can be used to perform such testing. Silk yarns with different properties are first selected, treated with the appropriate reagent solutions, dried and handloom-woven in one step into an integrated fabric chip. This platform has the unique advantage of scaling up production using existing and low cost physical infrastructure. We have demonstrated the ability to create pre-defined flow paths in fabric by using wetting and non-wetting silk yarns and a Jacquard attachment in the loom. Further, we show that yarn parameters such as the yarn twist frequency and weaving coverage area may be conveniently used to tune both the wicking rate and the absorptive capacity of the fabric. Yarns optimized for their final function were used to create an integrated fabric chip containing reagent-coated yarns. Strips of this fabric were then used to perform a proof-of-concept immunoassay with sample flow taking place by capillary action and detection being performed by a visual readout.

Properties and Customization of Sensor Materials for Biomedical Applications

“…Moreover, the system must be low cost, while still being robust, miniature, flexible, washable, reusable, or disposable (5). All these requirements point to microfluidic devices as the key for improving wearable chemo-and biosensing (338). Chemical measurements on bodily fluids such as blood, sweat, and urine are needed.…”

Exploration of microfluidic devices based on multi-filament threads and textiles: A review

“…These authors demonstrated that the procedure had made the silk more hydrophilic and enabled it to wick a predefined volume of coloured dye solution. 7 Nilghaz et al have used sewn cotton cloth which is inherently wettable and hydrophilic due to the porous structure of cloth formed by the gaps between the woven threads. They demonstrated that this porous structure is sufficient for providing capillary force and rapid wetting and wicking.…”

“…The wicking rates of low ($3 TPI), medium ($20 TPI), and high ($50 TPI) yarns were examined and it was observed that the wicking rate was increased by increasing the twist/inch. 7 Das et al modeled liquid wicking of polyester yarns and textile against gravity using the Laplace and the Hagen-Poiseuille equations, and considering the effect of gravity. In their study, pore geometry, liquid contact angle with fibre, number of fibres in a yarn, fibre denier, fibre cross-sectional shape, yarn denier, and twist level in the yarn were considered.…”

“…[4][5][6][7][8][9][10][11] Although the porous fibre structures in threads provide capillary channels, some natural fibres are coated waxes composed of long fatty acid chains; the natural plant wax reduces or even stops the liquid wicking within threads. 4,6,8,12 Wettability of these fibres can be enhanced by removing the natural waxes from the fibre surface, allowing wicking by capillary action to occur.…”

“…[1][2][3] As part of a continuous effort to seek new materials for making low-cost diagnostic devices, threads and fabrics have been investigated as a group of inexpensive materials for the fabrication of disposable microfluidic devices. [4][5][6][7][8] Thread normally refers to twisted fibers and can be combined to make a yarn. The voids between these fibres form capillary channels and facilitate liquid flow without the requirement of external pumping, make them suitable for fabricating rapid and inexpensive point-of-care (POC) diagnostics.…”