small talks: talks by students, for students <style type="text/css">  </style> </head> <body> <center>  <a href="http://dmse.mit.edu/"><img border=0 src="course3.jpg"></a> <a href="http://web.mit.edu/gso/faq/studentlifefee.html"><img border=0 src="gso.jpg"></a>  <a href="index.shtml"><b><font size=7><font color=black>small</font>TALKS</font><b></a> <a href="http://mtlweb.mit.edu/researchgroups/mems/"><img border=0 src="memsatmit.jpg"></a> <a href="http://rleweb.mit.edu/"><img border=0 src="rle.jpg"></a> <br> ♦ <i>talks by students, for students</i> ♦<br> Wednesdays, 4pm, 6-104<br> <a href="sponsors.shtml">sponsors</a><br> <a href="about.shtml">about small talks</a> </center> <p> <u>October 10, 2007</u> Hayden Taylor (EECS)<br> <i>The embossing of thermoplastic polymeric materials for micro- and nanofluidic device manufacture: current engineering challenges</i><br> <h4>Abstract:</h4> <p> The hot-embossing of thermoplastic layers has in recent years proved to be both a lithographic technique with exceptional lateral resolution and an attractive way of manufacturing medium-to-large quantities of micro- and nanofluidic devices. This talk highlights some of the work being done as part of the Singapore-MIT Alliance's flagship research project in polymeric microfluidic manufacturing systems and technology. <p> In hot micro-embossing, a thermoplastic polymeric substrate is heated above its glass transition temperature, and a hard stamp, carrying the pattern to be reproduced, is pressed into the softened substrate. The polymer is then cooled and the stamp is removed from the substrate. <p> There are three main challenges facing hot micro-embossing. Firstly, we need to understand the visco-elasto-plastic properties of the materials being used in order to replicate intricate topographies faithfully at the micron scale. Secondly, embossing stamps need to be capable of being withdrawn from the cooled, contracted polymeric substrate without fracturing, and must survive enough processing cycles to make the embossing process economically attractive. To this end, silicon, metallic, metallic glass and polymeric stamps and several stamp surface treatments are being investigated, as is the removal of the stamp from the polymeric substrate at or near the embossing temperature. The third challenge is to be able to produce embossed parts with surface properties that are appropriate for the mainly biomedical applications of the resulting devices. <p><p> <center> <small>Questions? Comments? Would you like to give a small talk?<br> [small-talks at mike india tango dot edu]<br> Oh, and sign up for our <a href="http://mailman.mit.edu/mailman/listinfo/small-talks-announce">announce list</a>! :)</small> </center> </body> </html>