The purpose of this thesis is to introduce a novel method of dry micro-object manipulation and to demonstrate predictable vision-based control. The Lift and slide conveyors presented utilize three main components: pads, lifters and a floating platform. The pads have a small planar displacement in the XY axis and lifters have a small Z axis displacement. Together they can be used to create minute displacements per cycle while carrying a floating platform that can hold the desired objects to be moved. These platforms can be handed off to other pad-lifter groups to create an unlimited planar envelope. Two degree of freedom control was established using LabView with open and closed loop routines. A model is presented that predicts the resonance frequencies with different loading and geometric characteristics to aid in design optimization for various applications. Parameters such as velocity, drift and traction are well characterized for different operating conditions.

<p>Microrobots have a promising prospect to be used in healthcare and bioengineering applications due to their capability to gently access small and delicate body sites. Unfortunately, traditional materials used for the fabrication of microrobots are rigid, hindering safe operation due to the transfer of high stresses to the surrounding tissue. Additionally, traditional microrobots are often not biocompatible, which threatens the health of the patient if not properly retrieved. This dissertation describes the fabrication and actuation of small-scale (several micrometers in all dimensions) magnetic robots that are soft, biocompatible, and capable of moving over smooth and corrugated surface. <u>S</u>oft <u>M</u>agnetic <u>M</u>icro <u>R</u>obots (SMµRs) can carry payloads in their porous interior and release them using external magnetic inputs. SMµRs has therefore the potential to be used in a wide range of applications—including targeted drug release and remote biosensing and bio sampling—and access a number of difficult-to-reach sites in the human body, such as intestines or blood vessels. The structure of SMµRs consist of three thin layers: Two layers of polymer with embedded magnetic particles aligned along a preferential direction. One porous layer, in between the magnetic layers, where the SMµRs can accumulate and release payloads. SMµRs are small, light in weight, and fast and inexpensive to fabricate. Moreover, the manufacturing of SMµRs is compatible with large-scale production processes, facilitating their future commercial exploitation. Using external rotating magnetic fields, the position of the SMµRs can be controlled wirelessly <i>via</i> tumbling locomotion. We demonstrate two types of tumbling locomotion (length-wise and side-wise) as well as the possibility to release the internal payload of the SMµRs in a discrete or continuous manner using only changes in the intensity of the external magnetic field. We studied the performance of SMµRs under a variety of environmental conditions as well as their capability of overcoming obstacles.</p>

There exists a need for a new class of underwater vehicle that can perform both close control tasks, as well as long-range exploration, without manual reconfiguration. A tetherless underwater vehicle (TUV) with acoustic communications to an operator station has potential to fulfill this need, while also removing much of the operating costs associated with tether management. The problem with TUVs is the limited communications bandwidth and time lag increasing with range from the transmitter. This thesis introduces a new class of controller for TUV vehicles that isolates the operator from the time-varying delay. This isolation is achieved through the formation of a continuum of control comprised of existing control paradigms, such as predictive and autonomous control. A smooth evolution through the continuum is formulated based on the time delay. The resulting controller permits operator close control for extended ranges without manual reconfiguration of the vehicle or controller.

Micromotors are recognized as promising candidates for untethered micromanipulation and targeted cargo transport. Their future application is, however, hindered by the low efficiency of drug encapsulation and their poor adaptability in physiological conditions. To address these challenges, one potential solution is to incorporate micromotors with biological materials as the combination of functional biological entities and smart artificial parts represents a manipulable and biologically friendly approach. This dissertation focuses on the development of custom-designed micromotors combined with sperm and their potential applications on targeted diseases treatment. By means of 2D and 3D lithography methods, microstructures with complex configurations can be fabricated for specific demands. Bovine and human sperm are both for the first time explored as drug carriers thanks to their high encapsulation efficiency of hydrophilic drugs, their powerful self-propulsion and their improved drug-uptake relying on the somatic-cell fusion ability. The hybrid micromotors containing drug loaded sperm and constructed artificial enhancements can be self-propelled by the sperm flagella and remotely guided and released to the target at high precision by employing weak external magnetic fields. As a result, micromotors based on both bovine and human sperm show significant anticancer effect. The application here can be further broadened to other biological environments, in particular to the blood stream, showing the potential on the treatment of blood diseases like blood clotting. Finally, to enhance the treatment efficiency, in particular to control sperm number and drug dose, three strategies are demonstrated to transport swarms of sperm. This research paves the way for the precision medicine based on engineered sperm-based micromotors.