Jeremy W. Burdon

A miniaturized cyclic PCR device—modeling and experiments

Abstract With the aid of thermal and fluidic modeling using CFDRC ACE+™, we designed and fabricated the first miniaturized cyclic polymerase chain reaction (PCR) device in low-temperature cofired ceramics. The device comprises of a serpentine channel with different cross-sectional areas in different reactor zones to provide adequate residence time for the melting, annealing, and extension reaction to take place. This is in contrary to the thermal cycling in the batch PCR system. With a flow rate of 15 μl/min, the designed time to complete 30 PCR cycles is less than 40 min, given the total volume of the device 19 μl, provided an internal pump may be implemented to reduce the dead volume. We have demonstrated DNA amplification in this device, using an external peristaltic pump, and the PCR product was used with a DNA bioelectronic sensor chip (Motorola e-Sensors™) for genotyping experiment.

Add Ceramic “MEMS” to the Pallet of MicroSystems Technologies

Just as the 40+ years of technology developments associated with the electronic application of semiconductor fabrication processes is “morphing” into a micro-electro- mechanical systems (MEMS) technology in the past dozen years or so, so it seems may the “mature” multilayer ceramic fabrication technology associated with capacitor components and interconnect substrates for the integrated circuit industry, be morphed into MEMS – microsystems technology applications. This paper highlights work underway in Motorola Labs aimed at exploring the potential to develop 3D multilayer ceramic structures to integrate (monolithic and hybrid) multiple functions to create microsystems for wireless, energy and life science applications. By multiple functions, we refer to the ability for a microsystem to perform electronic, fluidic, thermonic, photonic and mechatronic (or actuator) based functions. Current capabilities of the multilayer ceramic materials and processes to achieve integrated functionalities for wireless applications will be described including the development of a new dielectric enabling increased performance for wireless applications. Also to be highlighted will be exploratory microscale fuel cell prototypes exploiting advances in the multilayer ceramic lamination and feature forming technologies enabling the insertion of 3D microchannels for microfluidic functions. These prototypes also feature the ability of the technology to provide thermonic functionality for microreactor devices. Feasibility of a light source that can be integrated into the technology platform hinting at photonic applications will be described. Many materials science and engineering advancements are needed to achieve the potential of this “old” but newly “morphing” technology and some of these will be noted.

Ceramic magnetohydrodynamic (MHD) micropump

Magnetohydrodynamic (MHD) pumping has several attractive features including no-moving-parts operation, compatibility with biological solutions, and bi-directional pumping capability. In this work, a re-circulating ceramic MHD micropump is described. The MHD operation principle is based on the generation of Lorenz forces on ions within an electrolytic solution by means of perpendicular electric and magnetic fields. These Lorenz forces propel the ions through a channel, thus creating a net flow with no moving parts. Fabrication of the pumps is achieved by means of a new ceramic MEMS (CMEMS) platform in which devices are built from multiple layers of green-sheet ceramics. The major advantage to this technology is that unlike many other fabrication technologies, the multi-layer ceramic CMEMS platform is truly three-dimensional, thus enabling the building of complex integrated systems within a single platform. The ceramic-based MHD pumps have been analyzed and tested using both finite element modeling and experimental validation. Test results indicate that the pumps are capable of pumping a wide range of biological fluids in the flow rate range of microliters per minute. Additionally, good stability over 24 hours and good correlation with modeling data have been verified.