| The capability of detecting distributed static and dynamic loads is indispensable in a wide variety of applications, such as examining anatomical structures of biological tissues in tissue health analysis and minimally invasive surgery (MIS) and determining the texture of an object in robotics. This dissertation presents a comprehensive study of a polymer-based microfluidic device with electrolyte-enabled distributed transducers and demonstrates a new concept on using a single microfluidic device for distributed-load detection, which takes advantage of the low-cost microfluidic fabrication technology and the low modulus and biocompatibility of polymer. The core of the device is a single deformable polymer microstructure integrated with electrolyte-enabled transducers. While distributed loads are converted to different levels of deflections by the polymer microstructure, the deflections of the microstructure are translated to resistance changes by the five pairs of distributed transducers underneath the microstructure. Firstly, the design and working principle of the device is described. Then, due to its simple but efficient configuration, a standard fabrication process well developed for polydimethylsiloxane(PDMS)-based microfluidic devices is detailed and employed to fabricate this device. After that, the experimental setups for characterizing the device performance in static, step and sinusoidal inputs are illustrated. The experimental data then are collected and processed by using custom-built electronic circuits and custom LabVIEW/Matlab program to characterize the device performance. Lastly, the performance analysis of the device is conducted to obtain the performance parameters such as device sensitivity and load resolution. In summary, this polymer-based microfluidic device not only demonstrates the new concept and the capability of detecting distributed static and dynamic loads with a single device, with a thorough experimental study on the performance and characterization of this PDMS-based microfluidic device to correlate the device performance to its design parameters, but also the potential application of directly adopting this experimental method to measure the elasticity/viscoelasticity of a soft tissue. |
