Micro-Electro-Mechanical-Systems (MEMS) technology enables us to design and fabricate transducers matching the length scale of a biological cell.  With this unprecedented capability, we can interrogate and manipulate cells for diagnostic or therapeutic purposes.

Micro diagnostic systems are developed for specific and sensitive detection of biomarkers secreted from the cells or in fluid containing lysed cells. The system consists of microfluidic circuitry and molecular sensor. Moving, stopping, mixing and separation of fluids and particles are the fluidic processes for preparing biological sample ready for sensing the bio molecules.  The challenge of perfecting the sample preparation in microscale is the presence of macro complex molecules commonly found in the bio-fluid flows. The background noise a biomarker sensor is always the limiting factor of limit of detection (LOD). 

Micro implantable systems or drug screening systems need to interface with live cells which make the task become extremely challenging.  Cell consists of a large number of macro functional molecules. Cellular activities are manifestations of intra- and inter-molecular transports, motions of cellular molecules, and signaling pathway regulation. Design an engineering system to interact with a biological complex system to achieve a well defined goal leads toward an extremely rich research field.