PCB Escape Routing and Layer Minimization for Digital Microfluidic Biochips

Stationary-Mixing Field-Programmable Pin-Constrained Digital Microfluidic Biochip

“…Prior work has shown that the foremost cost-drivers for PCB-based DMFBs are the number of PCB layers, followed by the number of control pins [36]. The most expensive DMFBs are typically those that employ direct addressing, i.e., each control pin drives exactly one electrode; the number of PCB layers is determined by an escape route, which connects each internal electrode to a control pin on the perimeter of the chip [37,38]. The quality of the escape routing algorithm can significantly impact the number of PCB layers required.…”

“…Pin-sharing [39] allows one control pin to drive several electrodes, which reduces the total number of signals that must be delivered to the PCB, thereby reducing cost. Overly aggressive pin-sharing can be detrimental to PCB escape routing when a single wire must connect electrodes across the entire 2D span of the chip, creating blockages that push other wires onto additional PCB layers; this impact can be tempered with algorithmic enhancements that synergistically optimize pin sharing with escape routing [37,38]. The vast majority of pin-sharing schemes that have been proposed previously produce application-specific designs [37][38][39].…”

“…Overly aggressive pin-sharing can be detrimental to PCB escape routing when a single wire must connect electrodes across the entire 2D span of the chip, creating blockages that push other wires onto additional PCB layers; this impact can be tempered with algorithmic enhancements that synergistically optimize pin sharing with escape routing [37,38]. The vast majority of pin-sharing schemes that have been proposed previously produce application-specific designs [37][38][39]. One exception is called a Field-Programmable Pin-Constrained (FPPC) DMFB [36,40], which was general-purpose and could be fabricated with one or two PCB layers depending on the PCB technology parameters and the amount of flexibility build into the droplet transport busses.…”

“…Concurrent droplet routing in opposite directions is not possible using a three-phase bus (a) but becomes possible with a direct-addressing bus (b).A. Abdoli, P. Brisk Microelectronics Journal 77 (2018)[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48] …”

Mobility based Net Ordering for Simultaneous Escape Routing

“…Escape routing is of three types [15]: 1) Unordered escape routing where there is no particular sequence of pin escaping towards component boundary from a single component [15]- [21]; 2) ordered escape routing where there is a particular sequence (order) of pin escaping towards component boundary from a single component [22] (one of the example of this type of routing is Bus escape which is also called as maximum disjoint subset problem [23]); and 3) simultaneous escape routing where pins from multiple components escaped in the same order. This problem relatively more complex as compare to other escaping problems.…”