diff --git a/frappy_psi/razorbill.py b/frappy_psi/razorbill.py
new file mode 100644
index 0000000..7ee8c01
--- /dev/null
+++ b/frappy_psi/razorbill.py
@@ -0,0 +1,142 @@
+# *****************************************************************************
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Module authors:
+#   Paul M. Neves <pmneves@mit.edu>
+# *****************************************************************************
+
+from frappy.core import Readable, Parameter, FloatRange, HasIO, StringIO, Property, IntRange,\
+    IDLE, BUSY, WARN, ERROR, Drivable, BoolType, Attached, Writable, StructOf
+
+
+class Temp(Writable):
+    """stores sample temperature"""
+
+    target = Parameter('target voltage', FloatRange(0, 325, unit='K'),
+                            readonly=False)
+
+    def write_target(self, target):
+        self.value = target
+
+    def read_value(self):
+        return self.value
+    
+
+class Displacement(Readable):
+
+    # attached classes for capacitance and temperature
+    cap = Attached()
+    temp = Attached()
+
+    # modifying a property of inherited parameters (unit is propagated to the FloatRange datatype)
+    value = Parameter('displacement', FloatRange(None, None, unit='um'), readonly=True)
+    alpha290K = Parameter('capacitor constant at 290 K', FloatRange(None, None, unit='um pF'), readonly=False)
+    d0 = Parameter('offset displacement', FloatRange(None, None, unit='um'), readonly=False)
+    Cp = Parameter('parallel capacitance', FloatRange(None, None, unit='pF'), readonly=False)
+    d0_curve = Parameter('calibration curve for offset displacement',
+                      StructOf(a=FloatRange(None, None, unit='um'),
+                               b=FloatRange(None, None, unit='um/K'),
+                               c=FloatRange(None, None, unit='um/K^2'),
+                               d=FloatRange(None, None, unit='um/K^3'),
+                               e=FloatRange(None, None, unit='um/K^4'),),
+                      readonly=False)
+
+    def read_value(self):
+        # get temperature and capacitance
+        temp = self.temp.target
+        cap = self.cap.value
+
+        # calculate displacement from temperature and capacitance
+        d0_T = self.d0_curve['a'] + self.d0_curve['b']*temp + self.d0_curve['c']*temp**2 + self.d0_curve['d']*temp**3 + self.d0_curve['e']*temp**4
+
+        disp = self.alpha290K / (cap - self.Cp) - self.d0 + d0_T
+
+        return disp
+
+
+class Force(Readable):
+
+    # attached classes for capacitance and temperature
+    cap = Attached()
+    temp = Attached()
+
+    # modifying a property of inherited parameters (unit is propagated to the FloatRange datatype)
+    value = Parameter('force', FloatRange(None, None, unit='N'), readonly=True)
+    alpha290K = Parameter('capacitor constant at 290 K', FloatRange(None, None, unit='N pF'), readonly=False)
+    f0 = Parameter('offset force', FloatRange(None, None, unit='N'), readonly=False)
+    Cp = Parameter('parallel capacitance', FloatRange(None, None, unit='pF'), readonly=False)
+    f0_curve = Parameter('calibration curve for offset force',
+                      StructOf(a=FloatRange(None, None, unit='N'),
+                               b=FloatRange(None, None, unit='N/K'),
+                               c=FloatRange(None, None, unit='N/K^2'),
+                               d=FloatRange(None, None, unit='N/K^3'),
+                               e=FloatRange(None, None, unit='N/K^4'),),
+                      readonly=False)
+
+    def read_value(self):
+        # get temperature and capacitance
+        temp = self.temp.target
+        cap = self.cap.value
+
+        # calculate force from temperature and capacitance
+        alpha = self.alpha290K * (0.91 + 5e-5*temp + 9e-7*temp**2)
+        f0_T = self.f0_curve['a'] + self.f0_curve['b']*temp + self.f0_curve['c']*temp**2 + self.f0_curve['d']*temp**3 + self.f0_curve['e']*temp**4
+        
+        force = alpha / (cap - self.Cp) - self.f0 + f0_T
+
+        return force
+    
+
+class Stress(Readable):
+
+    # attached classes for displacement
+    force = Attached()
+
+    # modifying a property of inherited parameters (unit is propagated to the FloatRange datatype)
+    value = Parameter('stress', FloatRange(None, None, unit='GPa'), readonly=True)
+    area = Parameter('cross sectional area of sample in mm^2', FloatRange(None, None, unit='mm^2'), readonly=False)
+
+    def read_value(self):
+        return self.force.value / self.area / 1000
+
+
+class Strain(Readable):
+
+    # attached classes for displacement
+    displacement = Attached()
+
+    # modifying a property of inherited parameters (unit is propagated to the FloatRange datatype)
+    value = Parameter('strain', FloatRange(None, None, unit='m/m'), readonly=True)
+    L = Parameter('length of sample in mm', FloatRange(None, None, unit='mm'), readonly=False)
+
+    def read_value(self):
+        return self.displacement.value / (1000*self.L)
+    
+
+class YoungsModulus(Readable):
+
+    # attached classes for displacement
+    stress = Attached()
+    strain = Attached()
+
+    # modifying a property of inherited parameters (unit is propagated to the FloatRange datatype)
+    value = Parameter('Young\'s modulus', FloatRange(None, None, unit='GPa'), readonly=True)
+
+    def read_value(self):
+        if self.strain.value:
+            return self.stress.value / self.strain.value
+        else:
+            return 0
+