Laser microfabrication of a microheater chip for cell culture outside a cell incubator

Microfluidic chips have demonstrated their significant application potentials in microbiological processing and chemical reactions, with the goal of developing monolithic and compact chip-sized multifunctional systems. Heat generation and thermal control are critical in some of the biochemical processes. The paper presents a laser direct-write technique for rapid prototyping and manufacturing of microheater chips and its applicability for lab-on-a-chip cell culture outside a cell incubator. The aim of the microheater is to take the role of conventional incubators for cell culture for facilitating microscopic observation and/or other online monitoring activities during cell culture and provides portability of cell culture operation. Microheaters (5mm×5mm) have been successfully fabricated on soda-lime glass substrates covered with aluminium layer of thickness 120nm. Experimental results show that the microheaters exhibit good performance in temperature rise and decay characteristics, with localized heating at targeted spatial domains. These microheaters were suitable for a maximum long-term operation temperature of 120°C and validated for operation at 37°C for 48h. Results demonstrated that the microheaters are suitable for the culture of immortalised cell lines. The growth and viability of SW480 colon adenocarcinoma cells cultured the developed microheater chip were comparable to the results obtained in a conventional cell incubator.