Prof. Richard Crooks and doctoral student Hong Liu at the The University of Texas at Austin have developed an origami-inspired paper sensor which may be used to test for a variety of diseases. The sensor, cheekily dubbed “oPAD” (origami Paper Analytical Device), was designed as a low cost, parallel point of care testing device.
The sensor is based on similar technology to existing paper fluidics testing devices such as home pregnancy testing strips. A hydrophobic material, such as wax or photoresist, is patterned onto chromatography paper. These hydrophobic channels direct a test sample of urine, blood, or saliva to spots on the paper where test reagents have been embedded.
The origami approach adopted by the researchers means that several tests may be run simultaneously using a single sample at an extremely low cost. The sensor is so easy to develop it could potentially be fabricated using an inkjet printer, some special inks for the reagents and some neat folding. The researchers have also been experimenting with a low cost, pee-powered, battery system for the sensor, to facilitate tests that require an energy source. Salt in the urine samples acts as an electrolyte for the battery to power the sensor.
The results of the team’s experiments with the oPAD were published in October in the Journal of the American Chemical Society and details of the battery system were published last week in Analytical Chemistry. Provocative titles aside, we think this is a fantastic innovation and are looking forward to seeing how it progresses from here.
Abstract in Journal of American Chemical Society: Three-Dimensional Paper Microfluidic Devices Assembled Using the Principles of Origami
Abstract in Analytical Chemistry: Paper-Based Electrochemical Sensing Platform with Integral Battery and Electrochromic Read-Out