Magnetically modified PDMS microtools for micro particle manipulation

In this paper we describe novel magnetically driven polymeric microtool for non-intrusive and no contamination experiments on a chip. The composite is formed by suspending magnetite particles (Fe₃O₄) in polydimethylsiloxane (PDMS). In order to obtain precise and complicated pattern of micromagnetic tools, a photolithography techniques has been applied by making good use of thick KMPR-1050 photoresist as sacrificed mould. The surface of the produced micromagnetic tools is specially coated in order to suppress stiction in the biochip. The novelties of these tools are 1. fabrication of any 2D shape, 2.softness (harmless to cells), 3. no contact actuation (no stiction), 4. mass production with low cost. Here we have demonstrated that the mass-produced versatile micromagnetic tools such as stirrer and valve. The potential impact of this technology includes sample selection and separation, cell immobilization, genetic operation, tracking, mixing and reaction techniques into portable microfluidic labs-on-a-chip, culture systems and cell loading system.