CO2 laser machining represents a flexible technique for the rapid fabrication of miniaturized polymer structures such as polymethylmethacrilate (PMMA) microfluidic devices. A model to estimate the main dimensions (depth and width) of laser machined channels is presented, depending on process parameters (incident power, scanning speed). Blind cavities, to be used as fluid collectors, are machined layer by layer using multiple overlapping sequences of straight grooves with different scanning directions. The proposed technique shows that the removal depth varies proportionally with the number of layers machined, while surface roughness is influenced by the grooves spacing and the orientation of the scanning direction between successive layers. A method for thermally bonding the PMMA sheets, constituting the 3D structure of the chip, is also presented. The combination of high temperatures and a low bonding pressures makes it possible to generate a bulk junction enabling good performances in terms of sealing characteristics
Experimental study on the influence of drill wear in CFRP drilling processes
ROMOLI, LUCA;DINI, GINO
2008-01-01
Abstract
CO2 laser machining represents a flexible technique for the rapid fabrication of miniaturized polymer structures such as polymethylmethacrilate (PMMA) microfluidic devices. A model to estimate the main dimensions (depth and width) of laser machined channels is presented, depending on process parameters (incident power, scanning speed). Blind cavities, to be used as fluid collectors, are machined layer by layer using multiple overlapping sequences of straight grooves with different scanning directions. The proposed technique shows that the removal depth varies proportionally with the number of layers machined, while surface roughness is influenced by the grooves spacing and the orientation of the scanning direction between successive layers. A method for thermally bonding the PMMA sheets, constituting the 3D structure of the chip, is also presented. The combination of high temperatures and a low bonding pressures makes it possible to generate a bulk junction enabling good performances in terms of sealing characteristicsI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
