Capillary Stamping of Functional Materials: Parallel Additive Substrate Patterning without Ink Depletion

Abstract

functional inks; in this way, substrates may be patterned with functional materials and tailored nanoparticle arrays may be generated. An ideal additive lithographic substrate patterning technique would allow the execution of an unlimited number of parallel large-area ink deposition steps characterized by short cycle times without process-intrinsic interruptions caused, for example, by ink depletion. However, stateof-the-art substrate patterning techniques do not meet this requirement. Contactless ballistic pattering methods including inkjet printing, aerosol jet printing [2] and laser-induced forward transfer [3] can, in principle, be carried out continuously because ink can continuously be supplied to the substrate. However, these methods involve serial pixel-by-pixel writing associated with limitations regarding patternable areas and/or throughput. Additive substrate patterning by microcontact printing [4] and variations thereof such as polymer pen lithography (PPL), [5] capillary force lithography, [6] wet lithography, [7] and particle transfer printing [8] are parallel and allow simultaneous patterning of large substrate areas. However, these methods involve transfer of ink coated on the outer surfaces of solid elastomeric stamps to substrates. Consequently, ink depletion in the course of successive stamp-substrate contacts results in deteriorating quality of the stamped patterns. Automated stamping devices for parallel additive surface manufacturing would be commercially available, [9] but stamping needs to be interrupted after a limited number of stamping steps to recoat Patterned substrates for optics, electronics, sensing, lab-on-chip technologies, bioanalytics, clinical diagnostics as well as translational and personalized medicine are typically prepared by additive substrate manufacturing including ballistic printing and microcontact printing. However, ballistic printing (e.g., ink jet and aerosol jet printing, laser-induced forward transfer) involves serial pixelby-pixel ink deposition. Parallel additive patterning by microcontact printing is performed with solid elastomeric stamps suffering from ink depletion after a few stamp-substrate contacts. The throughput limitations of additive stateof-the art patterning thus arising may be overcome by capillary stampingparallel additive substrate patterning without ink depletion by mesoporous silica stamps, which enable ink supply through the mesopores anytime during stamping. Thus, either arrays of substrate-bound nanoparticles or colloidal nanodispersions of detached nanoparticles are accessible. Three types of model inks are processed: 1) drug solutions, 2) solutions containing metallopolymers and block copolymers as well as 3) nanodiamond suspensions representing colloidal nanoparticle inks. Thus, aqueous colloidal nanodispersions of stamped drug nanoparticles, regularly arranged ceramic nanoparticles by post-stamping pyrolysis of stamped metallopolymeric precursor nanoparticles and regularly arranged nanodiamond nanoaggregates are obtained. Capillary sta...

“Writing biochips”: high-resolution droplet-to-droplet manufacturing of analytical platforms

“…It has also been demonstrated that the same approach is suitable for printing inks of various types, such block copolymer poly(ferrocenyldimethylsilane)- block -poly(2-vinylpyridine), Fe/SiC nanoparticles, the drug, a solution of the contraceptive 17α-ethinylestradiol was stamped onto silanized glass slides. 37 The obtained patterns had lateral sizes at the submicron scale and good uniformity over cm 2 areas (Fig. 5).…”

“…To this aim, similar to the abovementioned concepts of silicon-based SPTs and NFBs, the porous polymeric stamps obtained by micromolding can be engineered to obtain ink reservoirs in the bulk of the polymer, 35,36 facilitating the continuous deposition of inks imbibed into the polymeric matrix. This approach has resulted in the recently developed capillary stamping, 37 a methodology in which elastomeric stamps, prepared with protocols similar to PPL, are prepared with a porous polymeric stamping layer, allowing for a continuous ink reservoir. Both approaches have been optimized for a vast plethora of inks and surfaces, opening up applications that make the abovementioned approaches suitable for biomolecular patterning and permitting a fine control of the deposited droplet volume.…”

“…This approach has been defined as capillary stamping. 37,120 The methodology is different from that of capillary force lithography, 121 in which a polymeric patterned mold comes in contact with a spin-coated polymeric thin film at temperature higher than the glass transition temperature of the polymer. This results in a negative copy of the mold pattern on the polymer film.…”

“…As an alternative to polymeric stamps, the same research group devised the use of spongy mesoporous silica stamps, prepared from the precursor or methyltrimethoxysilane. 35,37 Different from polymeric stamps, the silica-based stamps are characterized by a higher tolerability to inks based on organic solvents, and a lower tendency to interact with the ink molecules due to their methyl-terminated walls. In a first report, they set out a process to synthesize porous stamps by molding them against a macroporous silicon master.…”

Phenolic Resin Dual-Use Stamps for Capillary Stamping and Decal Transfer Printing

“…In particular, contact lithography with micropatterned stamps has been explored as parallel additive substrate manufacturing technique to produce components with tailored properties for electronics, optics, heat management, biomedical analytics, sensing, and many more applications. A first relevant embodiment of parallel additive contact lithography includes the transfer of ink from a stamp to a substrate by classical microcontact printing − and polymer pen lithography − using solid elastomeric stamps as well as by capillary stamping using porous homopolymer, block copolymer, − and silica , stamps. A second embodiment of parallel additive contact lithography is decal transfer microlithography, where parts of a stamp are lithographically transferred to a substrate. − The stamps are pressed against the substrate so that the stamps’ contact elements form tight contact with the substrates.…”