Cracks, formed during the drying of particulate films, can reduce the effectiveness or even render products useless. We present a novel, generic approach to suppress crack formation in thin films made from hard particle suspensions, which are otherwise highly susceptible to cracking, using the capillary force between particles present when a trace amount of an immiscible liquid is added to a suspension. This secondary liquid preserves the particle cohesion, modifying the structure and increasing the drying rate.Crack-free films can be produced at thicknesses much greater than the critical cracking thickness for a suspension without capillary interactions, and even persists after sintering. This capillary suspension strategy is applicable to a broad range of materials including suspensions of metals, semiconductive and ceramic oxides or glassy polymeric particles and can be easily implemented in many industrial processes since it is based on well-established unit operations. Promising fields of application include ceramic foils and printed electronic devices.1

Additional image material, g-codes for 3D-printing and numerical data are shown, further a short discussion on smart capillary suspensions in contrast to capillary nanosuspensions is presented. G-codes are available as separated files. 1 Supplementary images and graphs Figure S1: (a) Bright-field TEM micrograph and (b-d) TEM-EDXS mappings of sintered capillary suspension using paraffin oil as bulk phase. "# = 15 % alumina particles (*+,-= 5.5 µm) and /0" = 3 % aqueous sucrose solution (30 vol%) as secondary phase. The sample was sintered at 1350 °C for 2 h. Dark areas represent vacuum regions. Grey areas represent carbon areas. which are present due to TEM sample preparation. Si areas are represented yellow and Al areas in blue. (b) Showing all three mapped elements, (c) presenting only the Al fraction and (d) shows only Si fractions. The presented images were not processed with the salt-and-pepper median filter.

Shrinkage and dimensional accuracy are of particular importance for industrial material production. High dimensional accuracy directly lowers finishing works and cost. Capillary suspension processing is a novel, easy method to produce highly porous ceramic materials. Their shrinkage and shape accuracy is investigated during processing using a laser microscope. The total shrinkage is reduced by 20% for capillary suspension compared to pure suspension. This results from an increase in linear shape accuracy for top radii as well as height. The linear shape accuracy is increased by 6% in top radius and by 16% in height by using the capillary suspension phenomenon. We also show that this capillary suspension method is applicable for continuous shaping processes, like extrusion. The combination of an easy, robust processing route with known dimensional accuracy and applicability for continuous shaping processes makes this capillary suspension processing route highly desirable for industrial processes.