diff --git a/src/MaterialManager.py b/src/MaterialManager.py
index bdfbaa2..b011cf5 100644
--- a/src/MaterialManager.py
+++ b/src/MaterialManager.py
@@ -7,6 +7,9 @@ def __init__(self, params: list):
         self.params = params
         # other configurations
 
+    def changeMaterial(self, material) -> bool:
+        returnText = ""
+
     def changeMaterial(self, material) -> bool:
         returnText = ""
 
@@ -19,10 +22,21 @@ def changeMaterial(self, material) -> bool:
                 self.carManager.setMaterial(materialType.Carbon)
                 returnText = "Material is changed to Carbon."
 
+            case materialType.Vibranium:
+                self.carManager.setMaterial(materialType.Vibranium)
+                returnText = "Material is changed to Vibranium."
+
             case _:
-                returnText = "Material seletion is invalid."
+                returnText = "Material selection is invalid."
 
         return self._announceMaterial(returnText)
 
     def _announceMaterial(self, text: str) -> bool:
-        return self.announcer(text)
+        returnValue = False
+        try:
+            returnValue = self.announcer(text)
+        except:
+            print("Announcement of material type is failed.")
+            returnValue = False
+        finally:
+            return returnValue
diff --git a/src/Util.py b/src/Util.py
index 81ab0ba..6d47d02 100644
--- a/src/Util.py
+++ b/src/Util.py
@@ -1,3 +1,4 @@
 from enum import Enum
 
-materialType = Enum('Titanium', 'Carbon')
+# vibranium is specific to Steve's car
+materialType = Enum('Titanium', 'Carbon', 'Vibranium')
\ No newline at end of file