Laser Micromachining and Its Applications in Manufacturing of Micro Medical Devices

As the scale of manufacturing goes smaller and smaller, micro-scale or even nano-scale manufacturing becomes a trend in many applications. Laser micromachining is a good candidate for micro-scale manufacturing. The resolution of laser micromachining can be as small as the wavelength of the laser. It is capable of fabricating accurate structures in micro-scale. Biomanufacturing needs biocompatible materials and special processes to avoid contamination during manufacturing process. As a contactless manufacturing process, laser micromachining is also a good choice for biomanufacturing. Thus, laser micromachining has great potentials in micro-scale biomedical applications. However, compared with conventional manufacturing processes, laser micromachining has lots of special issues to be addressed. First of all, laser micromachining is a material-dependent process. Different materials show different machining performances in laser micromachining. Due to irregular cutting shape and laser energy profile, machined surface errors in laser micromachining are not as straightforward as in conventional manufacturing processes.;In this research work, we will develop the machining parameters for three biocompatible polymers: poly (methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS) and high density polyethylene. The effects of different laser energy, number of laser pulses per area and machining surfaces on the cutting parameters (cutting depth and width) and machining performances will be studied.;Based on the developed machining parameters, machined surface errors will be analyzed. The laser energy profile will be introduced. The sources of machined surface errors in laser micromachining will be discussed. An analytical model to calculate the machined surface errors considering the overlapping effects between two adjacent laser trajectories will be proposed. The experiment and simulation results show the model can accurately calculate and predict the machined surface errors.;Unlike conventional manufacturing process, in biomanufacturing the manufacturing techniques need to be integrated with living biological species to perform biomedical functions. In this work, an integrated biomanufacturing system will be proposed for design and manufacturing of biomedical devices in micro scale. In this proposed integrated biomanufacturing system, based on materials, input design and functional requirements, laser parameters can be selected according to our machining parameter development to achieve desirable geometric features. The process planning can be performed based on our machined surface error analysis model and input tolerance. Microstructures fabricated by the laser micromachining can be used in manufacturing of biomedical devices. Design and manufacturing of several types of biomedical devices will be discussed in this work.;Proteins play an important role in biomedical research. The interaction of Bovine Serum Albumin and laser micromachined polymer surfaces will be analyzed. With the capability of fabricating microstructures by laser micromachining and adsorption of proteins on laser micromachined surfaces, microstructures can be fabricated to guide the adherence and adsorption of protein on material surfaces. Since some proteins can facilitate cell attachment and growth, this kind of devices may be used as bio-interfaces or delivery tools to provide protein supply.;Electrical properties are usually interpreted as indicators for biosensors to detect and measure biological activities. Design and manufacturing of portable biomedical devices to characterize electrical properties of biological species will be discussed. The electrical properties of magnetotactic bacteria will be characterized by using this device.;In the general, this research work will discuss the laser micromachining techniques and explore the applications of laser micromachining in design and manufacturing of biomedical devices in micro scale. At the end of this work, future research work will be discussed.