Rapid Prototyping of Micropatterned Substrates Using Conventional Laser Printers

Abstract

We demonstrated rapid prototyping of templates for replica molding using a conventional laser printer. A polymer, polydimethylsiloxane, was cast directly on the transparency templates to make the replicas. The templates and replicas were characterized by scanning electron microscopy, profilometry, and optical microscopy. Four patterns, including an Electronic Industries Association resolution test pattern, were printed on transparencies at 600 dots per inch on a HP LaserJet 4M printer (Hewlett-Packard, Palo Alto, CA). Optimal precision and clarity occurred between intensity settings of 50-100. Mean pattern height/depth ranged from 8-13 m, and width was as small as a few tenths of a millimeter. Mean surface roughness of the template patterns ranged from 1 to 4 m on the top surface and from 5 to 10 nm on the bare transparency surface. This method provides access to microfabricated patterns for the broader research community without the need for sophisticated micromachining facilities.The interest in miniaturized systems for biochemical analysis and biomedical research continues to grow rapidly. Devices commonly referred to as micro total analytical systems (TAS) have been reported for a diverse range of applications, such as the determination of monoclonal antibodies, 1 the determination of phosphate 2 and nitrite, 3 and for high-speed DNA sequencing. 4 The application of similar devices to cell culture and cell mechanics 5 is also expanding to include the geometric control of cell shape, 6 orientation, and gene expression, 7 as well as the adhesion of neurons 8 and growth cone guidance. 9 The devices themselves usually require photolithographic microfabrication techniques to produce them since conventional machining will not provide sufficiently small devices (colloquially referred to as chips). A review by Madou provides information relating to all aspects of microfabrication. 10 Chip-based devices manufactured from glass are perhaps the most widely used in part because of the versatility and chemical resistivity of glass, the relatively straightforward fabrication, and the ease of optical detection in glass devices. However, a major problem frequently encountered by researchers without specialized facilities is how to produce prototype devices rapidly and at a realistic cost. This paper describes a practical method for the fabrication of templates, stamps, or molds using a laser printer with resolution of 600 dots per inch (dpi) or greater and solvent-free transparency film as a substrate (Fig. 1). The overall time from a computer design to a micropatterned surface is 14-24 h, most of which is for curing the polymer. No access to spin coaters, ultraviolet radiation, or tools normally found in the semiconductor process is

Print-and-Peel Fabrication for Microfluidics: What’s in it for Biomedical Applications?

“…In 2002, Shyy et al 11. reported replication of positive-relief patterns printed with an office LaserJet printer.…”

“…The patterns were printed on overhead transparencies, over which PDMS was cast. The reproduction of patterns of lines with different widths was tested 11. Several years later, Chen et al 6.…”

“…The submicrometer reproduction of the features (including the defects) of the LaserJet printed masters onto the surface of the PDMS slabs,11,76 suggests that the casting of the polymer does not set the resolution limits of PAP. Instead, the LaserJet printers set the lateral resolution of PAP 76…”

Toner and paper‐based fabrication techniques for microfluidic applications

“…The versatility of the direct-printing process allows it to produce masters or molds for rapid prototyping of polymeric devices. Two different groups [32,33] demonstrated that the printing of a toner layer on the transparency could be used as the positive relief of the masters. Examples of PDMS electrophoresis devices were successfully obtained and integrated to electrochemical detection of electroactive biological molecules and nonelectroactive inorganic ions [33].…”

Solid-ink-based print-and-peel method for microfluidic fabrication: a revisit

“…Two types of office-grade printers have been used for the PAP method: laser printer [2][3][4][5] and solid-ink printer [6][7][8]. Although laser printers can produce microfluidic molds based on the PAP method, solid-ink printers have an advantage that their solid ink can be printed on nearly any media [9].…”