Microelectrofludic benches for modular fluidic and electrical interconnections

Abstract

We present microelectrofluidic benches for modular fluidic and electrical interconnections. Previous methods are based on fluidic interconnection only by anodic bonding, tubing, and mechanical interlocking and involve high bonding temperature as well as large tubing waste volume. The present microelectrofludic benches have achieved fluidic and electrical interconnections with reasonable interconnection resistance in room temperature and reduced tubing waste volume into 3.14㎕. We design the microelectrofludic bench and the device-chip with respect to existing microfludic devices. Fluidic and electrical resistance in the microelectrofluidic bench is considered not to exceed the current operating performance of microfluidic devices. For easy alignment, we make protruded fluidic connector through PDMS molding with SU-8 double-expose-single-development process. In the experimental study, we perform the fluidic resistance test, the electrical resistance test, and the maximum pressure test with helium gas. In the fluidic resistance test, we use DI water and measure pressure drop in line, elbow, and interconnection. At flow rates from 10㎕/min to 100㎕/min, pressure drop occurs from 58.9Pa to 620Pa in 4mm-length channel and from 351Pa to 3010Pa in 24mm-length channel. We find that pressure drop in the elbow is small enough to lie within the maximum error bound of 0.098kPa at 70㎕/min and it is 2.25% of line resistance. Fluidic interconnection resistance is also small to lie within the maximum error bound of 0.065kPa at 100㎕/min and it is 0.56% of line resistance. In the electrical resistance test, we measure sheet resistance of 0.013±0.001Ω, and electrical line resistance varies from 2.2±0.35Ω to 6.5±0.39Ω depending on length. Electrical interconnection resistance is found to be 0.64±0.58Ω and this value is negligible compared to common electrical resistance in microfludic devices. In the maximum pressure test, we find it can stand up to 115±11.2kPa, 11 times higher than ...