TY - JOUR
T1 - Integrated lithographic molding for microneedle-based devices
AU - Lüttge, Regina
AU - Berenschot, Johan W.
AU - de Boer, Meint J.
AU - Altpeter, Dominique M.
AU - Vrouwe, E.X.
AU - Elwenspoek, Michael Curt
AU - van den Berg, Albert
N1 - 10.1109/JMEMS.2007.899339
PY - 2007/8
Y1 - 2007/8
N2 - This paper presents a new fabrication method consisting of lithographically defining multiple layers of high aspect-ratio photoresist onto preprocessed silicon substrates and release of the polymer by the lost mold or sacrificial layer technique, coined by us as lithographic molding. The process methodology was demonstrated fabricating out-of-plane polymeric hollow microneedles. First, the fabrication of needle tips was demonstrated for polymeric microneedles with an outer diameter of 250 $muhbox{m}$ , through-hole capillaries of 75-$muhbox{m}$ diameter and a needle shaft length of 430 $muhbox{m}$ by lithographic processing of SU-8 onto simple v-grooves. Second, the technique was extended to gain more freedom in tip shape design, needle shaft length and use of filling materials. A novel combination of silicon dry and wet etching is introduced that allows highly accurate and repetitive lithographic molding of a complex shape. Both techniques consent to the lithographic integration of microfluidic back plates forming a patch-type device. These microneedle-integrated patches offer a feasible solution for medical applications that demand an easy to use Point-of-Care sample collector, for example, in blood diagnostics for lithium therapy. Although microchip capillary electrophoresis glass devices were addressed earlier, here, we show for the first time the complete diagnostic method based on microneedles made from SU-8.$hfill$[2006-0110]
AB - This paper presents a new fabrication method consisting of lithographically defining multiple layers of high aspect-ratio photoresist onto preprocessed silicon substrates and release of the polymer by the lost mold or sacrificial layer technique, coined by us as lithographic molding. The process methodology was demonstrated fabricating out-of-plane polymeric hollow microneedles. First, the fabrication of needle tips was demonstrated for polymeric microneedles with an outer diameter of 250 $muhbox{m}$ , through-hole capillaries of 75-$muhbox{m}$ diameter and a needle shaft length of 430 $muhbox{m}$ by lithographic processing of SU-8 onto simple v-grooves. Second, the technique was extended to gain more freedom in tip shape design, needle shaft length and use of filling materials. A novel combination of silicon dry and wet etching is introduced that allows highly accurate and repetitive lithographic molding of a complex shape. Both techniques consent to the lithographic integration of microfluidic back plates forming a patch-type device. These microneedle-integrated patches offer a feasible solution for medical applications that demand an easy to use Point-of-Care sample collector, for example, in blood diagnostics for lithium therapy. Although microchip capillary electrophoresis glass devices were addressed earlier, here, we show for the first time the complete diagnostic method based on microneedles made from SU-8.$hfill$[2006-0110]
KW - IR-58776
KW - EWI-11309
KW - METIS-241628
U2 - 10.1109/JMEMS.2007.899339
DO - 10.1109/JMEMS.2007.899339
M3 - Article
SN - 1057-7157
VL - 16
SP - 872
EP - 884
JO - Journal of microelectromechanical systems
JF - Journal of microelectromechanical systems
IS - P2773/4
ER -