Over the past few decades,polydimethylsiloxane(PDMS)has become the material of choice for a variety of microsystem applications,including microfluidics,imprint lithography,and soft microrobotics.For most of these appl...Over the past few decades,polydimethylsiloxane(PDMS)has become the material of choice for a variety of microsystem applications,including microfluidics,imprint lithography,and soft microrobotics.For most of these applications,PDMS is processed by replication molding;however,new applications would greatly benefit from the ability to pattern PDMS films using lithography and etching.Metal hardmasks,in conjunction with reactive ion etching(RIE),have been reported as a method for patterning PDMS;however,this approach suffers from a high surface roughness because of metal redeposition and limited etch thickness due to poor etch selectivity.We found that a combination of LOR and SU8 photoresists enables the patterning of thick PDMS layers by RIE without redeposition problems.We demonstrate the ability to etch 1.5-μm pillars in PDMS with a selectivity of 3.4.Furthermore,we use this process to lithographically process flexible fluidic microactuators without any manual transfer or cutting step.The actuator achieves a bidirectional rotation of 50°at a pressure of 200 kPa.This process provides a unique opportunity to scale down these actuators as well as other PDMS-based devices.展开更多
基金BG is a Doctoral Fellow of the Research Foundation—Flanders(F.W.O.),Belgium.MDV acknowledges support from the ERC starting grant HIENA(no.337739).
文摘Over the past few decades,polydimethylsiloxane(PDMS)has become the material of choice for a variety of microsystem applications,including microfluidics,imprint lithography,and soft microrobotics.For most of these applications,PDMS is processed by replication molding;however,new applications would greatly benefit from the ability to pattern PDMS films using lithography and etching.Metal hardmasks,in conjunction with reactive ion etching(RIE),have been reported as a method for patterning PDMS;however,this approach suffers from a high surface roughness because of metal redeposition and limited etch thickness due to poor etch selectivity.We found that a combination of LOR and SU8 photoresists enables the patterning of thick PDMS layers by RIE without redeposition problems.We demonstrate the ability to etch 1.5-μm pillars in PDMS with a selectivity of 3.4.Furthermore,we use this process to lithographically process flexible fluidic microactuators without any manual transfer or cutting step.The actuator achieves a bidirectional rotation of 50°at a pressure of 200 kPa.This process provides a unique opportunity to scale down these actuators as well as other PDMS-based devices.
