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020			_aTHE0010073 (Local) _qHardback
040			_aUMPSA _beng _cUMPSA _erda
090			_aFTKPM .M87 2025 r Thesis
100	0		_aRaja Murfiqah Raja Mohamad Fouzy, _eauthor.
245	1	0	_aInvestigation of microlens array (MLA) replicated on polymer and glass substrates using partial filling hot embossing assisted with CO2 laser irradiation / _cRaja Murfiqah Binti Raja Mohamad Fouzy
264		1	_aKuantan, Pahang : _bUMPSA , _c2025
264		4	_c© 2025
300			_axvii, 142 pages : _billustrations ; _c30 cm. + _e1 CD-ROM
336			_2rdacontent _atext
337			_2rdamedia _aunmediated
338			_2rdacarrier _avolume
347			_2rda _atext file _bPDF
500			_aFaculty of Manufacturing & Mechatronics Engineering Technology
502			_aThesis (Doctor of Philosophy) -- Universiti Malaysia Pahang – 2025
504			_aIncludes bibliographical references
520	3		_aMicro/nanostructures are essential in advanced technologies across industries such as biomedical, electronics, imaging, and optics. This study explores the integration of partial filling hot embossing (PFHE) with CO₂ laser irradiation for fabricating microlens arrays (MLAs) on polymer and glass substrates. The CO₂ laser eliminates the need for preheating, soaking, holding, and cooling steps, reducing thermal cycle time from 15 minutes to under 10 seconds. This approach enhances efficiency and reduces costs compared to conventional hot embossing. Conventional hot embossing experiments demonstrated that temperature, pressing load, and holding time significantly influence replication quality. Elevated temperatures soften thermoplastic materials like PMMA, improving mold filling through reduced viscosity. An optimal pressing load (1 MPa) ensures complete mold cavity filling, while insufficient load leads to incomplete formation. Similarly, holding time of 6 minutes produces precise MLA features by allowing thorough material flow, compared to inadequate results at shorter durations. The PFHE method with CO₂ laser irradiation leverages silicon molds' high transmittance and PMMA's strong optical absorption at a 10.6 μm wavelength. Optimized parameters— laser power (30 W), scanning speed (100 mm/s), and irradiation time (9 s)—achieve MLAs with lens diameters of 100 μm, 300 μm, and 500 μm, alongside a smooth surface finish (roughness of 0.032 μm). Lower power levels, insufficient irradiation times, or high scanning speeds result in incomplete patterns, while prolonged heating at slower scanning speeds (50 mm/s) causes deformation. This approach not only addresses challenges of conventional hot embossing but also enhances mold durability and process efficiency. The PFHE with CO₂ laser irradiation offers a fast, low-cost, and highthroughput solution for MLA fabrication, demonstrating strong potential for industrial applications and significant cost savings.
610	2	0	_aFaculty of Manufacturing & Mechatronics Engineering Technology _xDissertations
650		0	_aUniversities and colleges _xDissertations
650		0	_aTheses _xDissertations
942			_2lcc _cTHESIS