Porous

silicon

Porous silicon is a highly precise and structurally tunable material featuring defined, regularly arranged pores. The silicon materials provided by SmartMembranes are characterized by controllable pore geometries, reproducible structures, and high structural homogeneity.

The pore structure can be precisely defined and adapted to different requirements. Depending on the configuration, porous silicon is available as free-standing membranes or as one-sided closed templates, making it suitable for filtration, analytical, and structuring applications.

Owing to its mechanical stability, chemical purity, and favorable analytical properties, porous silicon is used as a functional substrate in filtration, analytics, and micro- and nanostructuring. In addition, it provides a versatile material platform for the development of new applications and technologies.

MakroPor

MakroPor is a product line of porous silicon featuring highly precise macropores and an exceptionally narrow pore diameter distribution. The variation in pore diameter is below 5% and remains constant along the entire pore length, ensuring excellent reproducibility in filtration and structuring applications.

The material is based on n-doped single-crystalline silicon, providing high structural homogeneity, well-defined electrical properties, and excellent process stability.

The pore arrangement is defined by targeted pre-structuring and is uniformly realized across the entire active area. Depending on the design, the pores are arranged in strictly ordered trigonal or square lattices, enabling highly reproducible structures. In addition to periodic arrangements, custom-defined geometries can be implemented.

MakroPor is available both as free-standing membranes with through-pores and as one-sided closed templates. Optional anisotropic post-processing allows round pores to be selectively reshaped into square cross-sections, providing additional degrees of freedom for structural design.

Thanks to its controllable pore geometry, high porosity, and mechanical stability, MakroPor is particularly suited for applications in filtration, analytics, microstructuring, and as a template for macrostructured systems.

Standardprodukte

Interpore distance	Pore diameter	Pore length	Pore arrangement
1,5 µm	1 µm	50, 200 µm	trigonal
4,2 µm	2,5 µm	50, 200 µm	trigonal
12 µm	5 µm	350, 500 µm	square
20 µm	8 µm	500 µm	square

Material Properties

Porendurchmesser anpassbar ab 1 µm bis 17 µm(größer möglich)

Porenabstand und Anordnung der Poren anpassbar durch Anfertigung einer Photomaske zur Vorstrukturierung

Standardabweichung < 5%

Durchflussmembranen mit symmetrischen Poren

Poröses Silizium mit einseitig geschlossenen Poren

Porentiefen von wenigen µm bis 500 µm

Porosität einstellbar ab 20%

thermisch stabil bis 1200ºC
(abhängig von der Umgebung)

funktionalisierbare Oberfläche

Pore diameter

Adjustable from 1 µm to 18 µm

Interpore distance and pore arrangement (fixed)

1.5 µm / 4.2 µm – trigonal
12 µm / 20 µm – square

Standard deviation

< 5%

Flow-through membranes

With symmetric pores

Porous templates

With one-sided closed pores

Pore depth

From a few micrometers (template) up to 500 µm

Porosity

Adjustable from 20%

Thermal stability

Up to 1200 °C (depending on the environment)

Chemical stability

Chemically inert in most solvents and acids; not resistant to strong bases

funktionalisierbare Oberfläche

Download MakroPor

Factsheet

Safety Data Sheet (SDS)

LasePor

LasePor is a product line of laser-structured silicon filters developed for applications requiring large, well-defined pores and high flow rates. As raw material, SmartMembranes uses highly polished Czochralski silicon wafers, ensuring high material purity and excellent surface quality.

The pores are created using precise laser micromachining, allowing pore diameter, geometry, arrangement, and spacing to be accurately defined. The pores are inherently conical, resulting in different pore diameters on the laser entry and laser exit sides. This creates two functionally distinct membrane surfaces, enabling defined flow direction and controlled filtration behavior.

Depending on the design, pores can be arranged in square or trigonal patterns. The laser-based structuring process ensures a high degree of structural homogeneity across the entire active filter area.

During processing, particular emphasis is placed on cleanliness, reproducibility, and low surface roughness. As a result, LasePor filters are ideally suited as filtration and analytical substrates, especially for optical, spectroscopic, and microscopic techniques such as FTIR and Raman analysis.

Thanks to their robust mechanical properties, the IR transparency of silicon, and the flexibility in geometric design, LasePor filters are well suited for applications in filtration, microplastic analysis, and analytical sample preparation, where large pore sizes, defined structures, and high flow rates are required.