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Title: A micro pump for drug delivery application using smart actuators
Author: Khazravi, Mojtaba
ISNI:       0000 0004 2747 7810
Awarding Body: University of Leeds
Current Institution: University of Leeds
Date of Award: 2012
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This thesis details the fabrication of a smart actuator driven micro pump. The proposed pump was designed to take the advantage of a smart actuator used in drug delivery applications. Although advances in medicine have improved patients' chances against most diseases, conventional treatments and medications are not yet entirely efficient in terms of curing some diseases. For critical diseases and those difficult to cure, such as cancer and diabetes, state-of-the-art drug delivery systems could improve the treatment process and control or otherwise eliminate the complications associated with various illnesses owing to improved and more efficient drug delivery. Diabetes has been chosen as the primary target disease to be addressed in this project. Since the introduction of insulin delivery pumps during the 1970s, this type of drug delivery system has improved significantly; however, drug delivery systems currently available have various intrinsic practical problems. For example, they are rather large and heavy, and carrying such bulky devices can limit patients' mobility and their daily activities. On the other hand, they require user intervention, which can compromise their effectiveness. Moreover, such devices must be attached securely to the body via a catheter and pipe in order to deliver the drug; therefore, a fully automatic and miniaturised patch-like drug delivery system could offer valuable advantages over current devices. This project's approach towards solving the problem is to devise a novel micro pump through the use of smart actuators. In the proposed micro pump, the actuator and the diaphragm are integrated into one single part, thus eliminating most of the pump's moving parts compared with conventional pumps. Moreover, novel diaphragm designs are proposed. Smart actuators have a wide range in terms of materials and specifications; they can be solid, like quartz crystal, or flexible, like ionic polymer gel. Based on the outcome of the literature review for smart actuators, the ionic polymer metal composite (otherwise referred to as IPMC) was chosen to run the proposed micro pump owing to its low power consumption and. driving voltage, as well as good power-to-weight ratio. In order to characterise the IPMC actuator behaviour, proper test rigs and devices were devised and maximum displacement and force for different actuator strips and diaphragm setups were measured. The work carried out on the required calculations, modelling and simulation, is reported for both strip and diaphragm actuators. The results of the experiments on strips, diaphragms and pumps are presented in the respective chapters, highlighting the fact that, by constraining the actuator in any way, their maximum force and displacement output will be limited; thus, novel diaphragm designs are proposed. The result of the actuator experiments and the requirements of the diabetic patients, as studied in the literature review, were used to design the. micro pump itself. For the diaphragm and pump chamber, a rectangular shape was chosen owing to improved alignment in the final patch layout and higher compatibility with various IPMC diaphragm designs. In order to maximise the pump efficiency, various valve designs were studied and tested. Owing to the small displacement of the diaphragm, the valve backlash and opening force were found to be vitally important. Furthermore, the calculations, modelling and simulation work carried out on the pump are presented in this thesis. The experiments on the proposed micro pump, with its novel diaphragm design, showed that the required amount of drug can be transferred in time. The fabrication of this pump is the first step towards achieving the ultimate goal of developing a cutting-edge disposable insulin drug-delivery patch in the future.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available