Thread Based Devices for Low-Cost Diagnostics

The need for low-cost diagnostic devices, both for developing and industrial countries, has led to the search for inexpensive matrixes that will allow the performance of analytical assays. One approach uses paper to create multiple microfluidic channels which allow analytes in urine or blood to flow to different detection zones the device. The choice of paper arises from its low-cost and its ability to wick biological fluids by capillary forces (i.e., an external power is not required to move fluid in a device). This chapter describes the use of a common material—cotton thread—as an alternative matrix for low-cost diagnostics. Thread-based devices can be fabricated using established techniques that rely on common house-hold tools for manipulating threads (e.g., sewing machines and looms). The fabrication schemes described here could potentially be adapted for large-scale manufacturing of diagnostic devices.