Session: 16-01-01: Poster Session: NSF-Funded Research (Grad & Undergrad)

Paper Number: 99416

99416 - Mechanics-Driven Structural Design and Manufacturing of Electrical Sensing Based Microfluidic Biomedical Devices for Pain Management and Urinalysis 

Microfluidic biomedical devices with 3D spatial structures are considered superior to conventional 2D channels, as they maximize interaction between fluids and sensing elements, and thus offer an ideal environment for monitoring multiple types of diseases in relevance of rich biofluids in human bodies. Meanwhile, such a transition from planar to complex steric 3D structures generates demand for novel fabrication and manufacturing technologies of microfluidic devices. Two examples of potential biomedical applications of 3D microfluidic devices are demonstrated in this poster, with breakthroughs in structural design and manufacturing techniques respectively. The first example will be a 3D porous structured microfluidic device applied as a urine analyzer. Urinalysis is a simple and non-invasive approach for the diagnosis and monitoring of body health. However, quantitative urinalysis is predominantly limited to low accessible clinical laboratories. At-home test strips provide timely and fast detection of biomarker substances in urine by 2D lateral flow through labeled strips, yet only provide qualitative data. 3D porous structures could offer a maximized space for urine to interact with sensing elements thus enhancing the sensitivity. The proposed research reports an electrical sensing based, low-cost, cellular microfluidic device that is enabled by soft, porous polydimethylsiloxane (PDMS) materials with full decorations of multiwalled carbon nanotubes (MWCNTs) and demonstrates its high sensitivity and rapid diagnosis of biomarkers in urine. A cyclic swelling/shrink process of PDMS scaffolds is developed to achieve uniform and dense decorations of MWCNTs onto porous PDMS scaffolds that provide an electrical sensing platform to physically interact with biomarkers during urine flow. The sensing capability, sensitivity and reusability (via sunlight exposure) of the device to monitor commonly existing biomarkers in urine are systemically demonstrated by programming mechanical deformation of porous scaffolds. Ex vivo experiments in disease mouse models show good agreement with results from parallel clinical laboratory testing, thus validating the design features and measurement accuracy and reliability of devices in urinalysis. In parallel with the effort of developing this novel 3D porous structured microfluidic urinalysis device, a modified 3D printing technique enables printing on curved substrate will be introduced as second example. Low back pain is one of the greatest public health problems worldwide. Microneedles allow direct permeation of drugs into the body by creating microchannels with relatively little or no pain. Using heat to accelerate the diffusion of drug molecules could be attractive if a single integrated heat-delivery system can be achieved with advanced manufacturing techniques. Hence, we proposed a drug-encapsulated microneedle patch system integrated with a 3D-printed microheater device and demonstrate that the drug delivery rate can be well controlled by regulating the temperature with the microheater. The printing ink solution consisting of MWCNTs and PDMS is proposed with the concentration of MWCNTs up to 45% (10 times higher than ever) and the 3D printing ability of microheater on various material and geometric types of substrates is demonstrated with a good agreement of theoretical prediction. Afterward, the adhesion between the printed pattern and the surface of microneedles is evaluated as the heating function operates, and a facile strategy is proposed to enhance their integration adhesion by tuning the ink solution. In vitro tests on rat skin are also conducted to assess the functional abilities of the microheater integrated microneedle patch system in drug delivery. The expected results and findings will serve as proof of concepts for developing next-generation biomedical devices and systems.

Presenting Author: Mengtian Yin University of Virginia

Presenting Author Biography: My research focuses on the design and practice of nano and micro scale fabrication for flexible electronics, with an emphasis on bio-integrated devices. Soft materials like polymers are utilized to help meet challenges in the exploration of this field. Integration of fundamental studies and experimental results has been employed to achieve my goals.

Authors:

Mengtian Yin University of Virginia
Baoxing Xu University of Virginia