Flexible packaging of solid-state integrated circuit chips with elastomeric microfluidics

TLDR

Traditional IC packaging methods such as wire‑bonding and flip‑chip bonding are incompatible with microfluidic technologies, creating a challenge for integrating electronics with fluidics. The authors propose a flexible elastomeric package that embeds smart electronics and microfluidics into a single integrated system. They fabricate microfluidic channels in PDMS that deliver liquid samples and liquid‑metal interconnects to the IC chip, enabling electrical connections within the elastomer package. The resulting system remains fully functional when bent to a 1 cm radius or strained by 15 %, demonstrating its suitability for wearable health monitoring, point‑of‑care diagnostics, and environmental sensing.

Abstract

A flexible technology is proposed to integrate smart electronics and microfluidics all embedded in an elastomer package. The microfluidic channels are used to deliver both liquid samples and liquid metals to the integrated circuits (ICs). The liquid metals are used to realize electrical interconnects to the IC chip. This avoids the traditional IC packaging challenges, such as wire-bonding and flip-chip bonding, which are not compatible with current microfluidic technologies. As a demonstration we integrated a CMOS magnetic sensor chip and associate microfluidic channels on a polydimethylsiloxane (PDMS) substrate that allows precise delivery of small liquid samples to the sensor. Furthermore, the packaged system is fully functional under bending curvature radius of one centimetre and uniaxial strain of 15%. The flexible integration of solid-state ICs with microfluidics enables compact flexible electronic and lab-on-a-chip systems, which hold great potential for wearable health monitoring, point-of-care diagnostics and environmental sensing among many other applications.