Transporting Digital Micro-fluids Among Multi-chips Based on Surface Acoustic Waves

A novel method of transporting digital microfluids among multichips by means of surface acoustic waves (SAW) has been proposed. The whole system is composed of three piezoelectric chips. One is an interface chip and the others are working chips. Each chip has an interdigital transducer (IDT) with a center frequency of 27.5 MHz and a reflector, which are fabricated on a 1280yx-cut lithium niobate (LiNbO3) substrate. A digital microfluid to be transported was first pipetted onto working chip 2 by a microsyringe. After the interface chip was adjusted to be the same height as working chip 2 with a gap as small as possible, an amplified RF signal with a frequency of 27.5 MHz was applied to the IDT of working chip 2. The IDT radiated SAW, which drove the digital microfluid to the interface chip. Similarly, this digital microfluid was transported from the interface chip to working chip1. As a demonstration, two digital microfluids on different working chips had also been successfully mixed and made to react by means of SAW.