Samples

Samples

A few examples of input text files and calculation results are shown here.

  1. Rectangular Hydrophilic Domain

    1. Creating More Than One Domains

    2. Copying Domains

    3. Creating Curved Domains

Rectangular Hydrophilic Domain

Here we simulate a 100-pL droplet placed on a substrate with a rectangular hydrophilic domain. The contact angles are 60 degree outside and 30 degree inside the rectangle.

Initial State (left) and Calculation Result (right)


UnitOfLength um // the unit of length you use

UnitOfVolume pL // the unit of volume you use

Grid 50 // the interval of grid lines (um)

Density 0 // the density of liquid (g/mL)

SurfaceTension 73 // the surface tension of liquid (mN/m)

Outside 60 // the default contact angle (degree)

Pattern 30 // create a new domain with the specified contact angle (degree)

P 60 40 // (x, y) of upper right corner (um)

P -60 40 // (x, y) of upper left corner (um)

P -60 -40 // (x, y) of lower left corner (um)

P 60 -40 // (x, y) of lower right corner (um)

Droplet 100 0 0 90 8 // create an initial droplet shape

// volume (pL), center position (x, y) (um),

// initial contact angle (degree), the division level of mesh

Line 1 & 2: Setting of units

The units should be declared in the begining of the text file.

You can choose unit of length (m, cm, mm, um, nm) and unit of volume (L, dL, mL, uL, nL, pL, fL).

If omitted, the default units are um and pL.

Line 4: Setting of Grid Line

Set the interval of grid lines.

If omitted, the interval is adjusted automatically.

Line 6, 7: Surface Tention and Density of the Liquid

These parameters are not essential.

By default, the density is zero, which means that the gravity is neglected.

The surface tension is necessary only when you take the gravity into account or when you need the absolute value of energy.

Line 9: Setting of Default Contact Angle

This contact angle is applied to the substrate surface which is not included in any domains.

Line 11-15: Create New Domain with New Contact Angle

Pattern command creates a new domain with the specified contact angle.

Then, a set of P commands defines the corners of the created domain.

Line 17: Create Initial Shape of Droplet

Droplet command creates a spherical droplet as an initial state.

Parameters are volume, center position (x, y), initial contact angle, and the division level of mesh.

Recommended values of the division level is about 8-16.

To Start Calculation

After opening this text file, press "Update: Auto" button to start the energy-minimization calculation.

The calculation usually finishes in a few seconds.

Then, press "Refine" button to make the mesh finer, and press "Update: Auto" button again.

Creating More Than One Domain

You can create any number of domain, and set different contact angles for the domains. Note that a domain mush not overlap other domains.

Initial State (left) and Calculation Result (right)


Outside 60 // contact angle is 60 degree outside the square

Pattern 50 // contact angle is 50 degree inside the right triangle

P 50 50 // corners of the right triangle

P -50 50

P 50 -50

Pattern 30 // contact angle is 30 degree inside the left triangle

P -50 -50 // corners of the left triangle

P 50 -50

P -50 50

Droplet 100 0 0 90 8

Copying Domains

You can copy domains by using CopyPattern command.

This command creates a set of domain copies with a specified translation operation.

Initial State (left) and Calculation Result (right)


Outside 60 // contact angle is 60 degree on the white surface

Pattern 30 // contact angle is 30 degree on the gray stripe

P -100 -500

P -90 -500

P -90 500

P -100 500

CopyPattern 20 0 9 // copy the gray domain 9 times with a shift of (20 um, 0 um) for each

Droplet 100 0 0 60 8

Creating Curved Domains

You can draw arc and bezier curve by Arc and Bezier commands.

In Arc command, please specify the starting point (x, y), the center (x, y), the rotation angle, and division number.

You can also draw the domain directly by mouse. (Select "Draw Pattern" mode in the tool bar.)

Initial State (left) and Calculation Result (right)


Grid 50

Outside 60

Pattern 30 // contact angle is 30 degree on the gray surface

Arc 50 0 0 0 180 18 // upper arc

Arc -50 0 -50 -50 -90 9 // lower left arc

Arc 0 -50 50 -50 -90 9 // lower right arc

Droplet 40 0 20 90 8 // 40-pL droplet is placed at the position (0 um, 20 um)

Format of the Input Text File

  • Write one command in one line. You can put blank lines at any places.

    • Commands are executed in order from the first line.

    • Commands are not case-sensitive.

    • Separate a command and each parameter with a space, comma, tab, or parenthesis.

    • You can put any comments after double slashes.

    • All the commands below give the same results.

VIEWANGLE 45 60 // delimited by tabs

ViewAngle 45, 60 // delimited by spaces and commas

viewangle(45, 60) // delimited by parenthesis