diff --git a/examples/SS316L.json b/examples/SS316L.json
index 6197ddf..bc09703 100644
--- a/examples/SS316L.json
+++ b/examples/SS316L.json
@@ -129,6 +129,18 @@
             "reference": "None",
             "uncertainty": "None",
             "print_symbol": "\\alpha"
+        },
+        "interface_response_function": {
+            "print_name": "Dendrite tip velocity",
+            "value_laurent_poly": [[0,0],[-0.000517783154178829,1],[0.000231067291419276, 2]],
+            "dependent_variable_print_name": "Undercooling",
+            "dependent_variable_print_symbol": "\\Delta T",
+            "dependent_variable_unit": "K",
+            "unit": "m/s",
+            "reference": "W. Tan, Y.C. Shin, Multi-scale modeling of solidification and microstructure development in laser keyhole welding process for austenitic stainless steel, Computational Materials Science 98 (2015) 446-458. DOI:  https://doi.org/10.1016/j.commatsci.2014.10.063",
+            "uncertainty": "None",
+            "print_symbol": "IRF",
+            "note": "These values are from a 2nd order polynomial fit with y-intercept of 0.0 (R^2 = 0.995) using data from the Fe-18.5Cr-12.5Ni line in Fig. A2"
         }
     },
     "note": "This file currently excludes the surface tension, marangoni coefficient, and the vapor pressure due to the need for function representations other than Laurent polynomials."
diff --git a/mistlib/core.py b/mistlib/core.py
index 03103f3..e8e4531 100644
--- a/mistlib/core.py
+++ b/mistlib/core.py
@@ -115,6 +115,7 @@ def __init__(self, file=None):
             "laser_absorption",
             "solidus_eutectic_temperature",
             "hall_petch_coefficient",
+            "interface_response_function",
         ]
 
         self.composition = {}
@@ -606,6 +607,40 @@ def write_additivefoam_input(
         self.write_additivefoam_thermoPath(file=thermo_file)
         return [transport_file, thermo_file]
 
+    def write_exaca_input(self, file="exaca_material_file.json"):
+        data = {}
+        eutectic_temp = self.properties["solidus_eutectic_temperature"].value
+        liquidus_temp = self.properties["liquidus_temperature"].value
+        data["freezing_range"] = liquidus_temp - eutectic_temp
+        # Get interface response function as a Laurent polynomial
+        irf = self.properties["interface_response_function"].value_laurent_poly
+        irf_dict = {}
+        for value, order in irf:
+            irf_dict[order] = value
+        if len(irf) == 4:
+            data["function"] = "cubic"
+            data["coefficients"] = {
+                "A": irf_dict[3],
+                "B": irf_dict[2],
+                "C": irf_dict[1],
+                "D": irf_dict[0],
+            }
+        elif len(irf) == 3:
+            data["function"] = "quadratic"
+            data["coefficients"] = {
+                "A": irf_dict[2],
+                "B": irf_dict[1],
+                "C": irf_dict[0],
+            }
+        else:
+            print(
+                f"interface_response_function must be polynomial of 3rd order or less for ExaCA input file"
+            )
+            raise ValueError
+        with open(file, "w", encoding="utf-8") as f:
+            json.dump(data, f, ensure_ascii=False, indent=4)
+        return file
+
     def write_3dthesis_input(self, file, initial_temperature=None):
         # 3DThesis/autothesis/Condor assumes at "T_0" initial temperature value. Myna populates this from Peregrine. For now we add a placeholder of -1 unless the user specifies an initial temperature.
         if initial_temperature == None:
diff --git a/tests/unit_tests.py b/tests/unit_tests.py
index 910276a..e112dc8 100644
--- a/tests/unit_tests.py
+++ b/tests/unit_tests.py
@@ -175,6 +175,18 @@ def test_write_adamantine(self):
             os.path.exists(adamantine_file_path), f"File {file} should exist."
         )
 
+    def test_write_exaca(self):
+        path_to_example_data = os.path.join(
+            os.path.dirname(__file__), "../examples/SS316L.json"
+        )
+        mat = mist.core.MaterialInformation(path_to_example_data)
+        material_filepath = mat.write_exaca_input()
+
+        # Asserts whether the files actually exist
+        self.assertTrue(
+            os.path.exists(material_filepath), f"File {material_filepath} should exist."
+        )
+
     def test_write_additivefoam(self):
         path_to_example_data = os.path.join(
             os.path.dirname(__file__), "../examples/SS316L.json"