diff --git a/libopenfpga/libarchopenfpga/arch/sample_arch.xml b/libopenfpga/libarchopenfpga/arch/sample_arch.xml
index 8338108fe..09a4833d2 100644
--- a/libopenfpga/libarchopenfpga/arch/sample_arch.xml
+++ b/libopenfpga/libarchopenfpga/arch/sample_arch.xml
@@ -9,26 +9,26 @@
   -->
 <openfpga_architecture>
   <technology_library>
-    <transistors name="logic" type="logic">
+    <device name="logic" type="transistor">
       <model type="academia" corner="TOP_TT" ref="M" path="${OPENFPGA_PATH}/openfpga_flow/tech/PTM_45nm/45nm.pm"/>
       <design vdd="0.9" pn_ratio="2"/>
       <nmos name="nch" chan_length="40e-9" min_width="140e-9" variation="logic_transistor_var"/>
       <pmos name="pch" chan_length="40e-9" min_width="140e-9" variation="logic_transistor_var"/>
-    </transistors>
-    <transistors name="io" type="io"/>
+    </device>
+    <device name="io" type="transistor"/>
       <model type="academia" corner="TT" ref="M" path="${OPENFPGA_PATH}/openfpga_flow/tech/PTM_45nm/45nm.pm"/>
       <design vdd="2.5" pn_ratio="3"/>
       <nmos name="nch_25" chan_length="270e-9" min_width="320e-9" variation="io_transistor_var"/>
       <pmos name="pch_25" chan_length="270e-9" min_width="320e-9" variation="io_transistor_var"/>
-    </transistors>
-    <rram name="mem_rram"> 
+    </device>
+    <device name="mem_rram" type="rram"> 
       <model type="academia" ref="X" path="${OPENFPGA_PATH}/openfpga_flow/tech/PTM_45nm/rram.pm"/>
-      <device rlrs="1e4" rhrs="1e5" variation="mem_rram_var"/> 
-    </rram>
-    <rram name="logic_rram">
+      <rram rlrs="1e4" rhrs="1e5" variation="mem_rram_var"/> 
+    </device>
+    <device name="logic_rram" type="rram">
       <model type="academia" ref="X" path="${OPENFPGA_PATH}/openfpga_flow/tech/PTM_45nm/rram.pm"/>
-      <device rlrs="5e3" rhrs="20e6" variation="logic_rram_var"/> 
-    </rram>
+      <rram rlrs="5e3" rhrs="20e6" variation="logic_rram_var"/> 
+    </device>
     <device_variation>
       <variation name="logic_transistor_var" abs_variation="0.1" num_sigma="3"/>
       <variation name="io_transistor_var" abs_variation="0.1" num_sigma="3"/>
diff --git a/libopenfpga/libarchopenfpga/src/technology_library.h b/libopenfpga/libarchopenfpga/src/technology_library.h
index 4f9600cbe..c062c7ec3 100644
--- a/libopenfpga/libarchopenfpga/src/technology_library.h
+++ b/libopenfpga/libarchopenfpga/src/technology_library.h
@@ -4,6 +4,8 @@
 /********************************************************************
  * This file include the declaration of technology library
  *******************************************************************/
+#include <string>
+#include "technology_library_fwd.h"
 
 /********************************************************************
  * Types for technology library attributes
@@ -16,26 +18,26 @@
  * PTM is the Predictive Technology Model provided by the Arizona
  * State University (ASU). Available at ptm.asu.edu
  *******************************************************************/
-enum e_tech_lib_type {
-  TECH_LIB_INDUSTRY,
-  TECH_LIB_ACADEMIA,
-  NUM_TECH_LIB_TYPES
+enum e_tech_lib_model_type {
+  TECH_LIB_MODEL_INDUSTRY,
+  TECH_LIB_MODEL_ACADEMIA,
+  NUM_TECH_LIB_MODEL_TYPES
 };
 /* Strings correspond to each technology library type */
-constexpr std::array<const char*, NUM_TECH_LIB_TYPES> TECH_LIB_TYPE_STRING = {{"industry", "academia"}};
+constexpr std::array<const char*, NUM_TECH_LIB_MODEL_TYPES> TECH_LIB_MODEL_TYPE_STRING = {{"industry", "academia"}};
 
 /********************************************************************
- * Types of transistor groups which may be defined in a technology library
- * We categorize the transistors in terms of their usage in FPGA architecture
- * 1. NMOS transistor 
- * 2. PMOS transistor 
+ * Types of device which may be defined in a technology library
+ * 1. transistor 
+ * 2. RRAM
  *******************************************************************/
-enum e_tech_lib_trans_type {
-  TECH_LIB_TRANS_NMOS, 
-  TECH_LIB_TRANS_PMOS, 
+enum e_tech_lib_device_type {
+  TECH_LIB_DEVICE_TRANSISTOR, 
+  TECH_LIB_DEVICE_RRAM, 
+  NUM_TECH_LIB_DEVICE_TYPES
 };
-/* Strings correspond to transistor type type */
-constexpr std::array<const char*, NUM_TECH_LIB_TYPES> TECH_LIB_TRANS_TYPE_STRING = {{"industry", "academia"}};
+/* Strings correspond to transistor type */
+constexpr std::array<const char*, NUM_TECH_LIB_DEVICE_TYPES> TECH_LIB_DEVICE_TYPE_STRING = {{"transistor", "rram"}};
 
 /********************************************************************
  * Types of transistors which may be defined in a technology library
@@ -43,19 +45,58 @@ constexpr std::array<const char*, NUM_TECH_LIB_TYPES> TECH_LIB_TRANS_TYPE_STRING
  * 2. PMOS transistor 
  *******************************************************************/
 enum e_tech_lib_trans_type {
-  TECH_LIB_TRANS_NMOS, 
   TECH_LIB_TRANS_PMOS, 
+  TECH_LIB_TRANS_NMOS, 
+  NUM_TECH_LIB_TRANS_TYPES
 };
-/* Strings correspond to transistor type type */
-constexpr std::array<const char*, NUM_TECH_LIB_TYPES> TECH_LIB_TRANS_TYPE_STRING = {{"industry", "academia"}};
+/* Strings correspond to transistor type */
+constexpr std::array<const char*, NUM_TECH_LIB_TRANS_TYPES> TECH_LIB_TRANS_TYPE_STRING = {{"pmos", "nmos"}};
 
 /********************************************************************
  * Process corners supported 
  *******************************************************************/
 enum e_process_corner {
- BEST_CORNER,
- TYPICAL_CORNER,
- WORST_CORNER
+  TECH_LIB_CORNER_FF,
+  TECH_LIB_CORNER_TT,
+  TECH_LIB_CORNER_SS,
+  NUM_TECH_LIB_CORNER_TYPES
+};
+/* Strings correspond to process corner type */
+constexpr std::array<const char*, NUM_TECH_LIB_CORNER_TYPES> TECH_LIB_CORNER_TYPE_STRING = {{"FF", "TT", "SS"}};
+
+/********************************************************************
+ * A data structure to describe technology library
+ *******************************************************************/
+class TechnologyLibrary {
+  private: /* Internal data */
+    /* Transistor-related fundamental information */
+    vtr::vector<TechnologyDeviceId, TechnologyDeviceId> device_ids_;
+    vtr::vector<TechnologyDeviceId, std::string> device_names_;
+    vtr::vector<TechnologyDeviceId, e_tech_lib_device_type> device_types_;
+    vtr::vector<TechnologyDeviceId, e_tech_lib_model_type> device_model_types_;
+    vtr::vector<TechnologyDeviceId, std::string> device_corners_;
+    vtr::vector<TechnologyDeviceId, std::string> device_model_refs_;
+    vtr::vector<TechnologyDeviceId, std::string> device_lib_paths_;
+    vtr::vector<TechnologyDeviceId, float> device_vdds_;
+    vtr::vector<TechnologyDeviceId, float> device_pn_ratios_;
+
+    /* Transistor models stored in vtr::Point data structure. pmos->x, nmos->y */
+    vtr::vector<TechnologyDeviceId, vtr::Point<std::string>> transistor_model_names_;
+    vtr::vector<TechnologyDeviceId, vtr::Point<float>> transistor_model_chan_lengths_;
+    vtr::vector<TechnologyDeviceId, vtr::Point<float>> transistor_model_min_widths_;
+    vtr::vector<TechnologyDeviceId, vtr::Point<std::string>> transistor_model_variation_names_;
+    vtr::vector<TechnologyDeviceId, vtr::Point<TechnologyVariationId>> transistor_model_variation_ids_;
+
+    /* ReRAM-related fundamental information */
+    vtr::vector<TechnologyDeviceId, vtr::Point<float>> rram_resistances_;
+    vtr::vector<TechnologyDeviceId, float> rram_variation_names_;
+    vtr::vector<TechnologyDeviceId, TechnologyVariationId> rram_variation_ids_;
+    
+    /* Variation-related fundamental information */
+    vtr::vector<TechnologyVariationId, TechnologyVariationId> variation_ids_;
+    vtr::vector<TechnologyVariationId, std::string> variation_names_;
+    vtr::vector<TechnologyVariationId, std::string> variation_abs_values_;
+    vtr::vector<TechnologyVariationId, std::string> variation_num_sigmas_;
 };
 
 #endif
diff --git a/libopenfpga/libarchopenfpga/src/technology_library_fwd.h b/libopenfpga/libarchopenfpga/src/technology_library_fwd.h
new file mode 100644
index 000000000..4055ff4f2
--- /dev/null
+++ b/libopenfpga/libarchopenfpga/src/technology_library_fwd.h
@@ -0,0 +1,24 @@
+/************************************************************************
+ * A header file for TechnologyLibrary class, including critical data declaration
+ * Please include this file only for using any TechnologyLibrary data structure
+ * Refer to circuit_library.h for more details 
+ ***********************************************************************/
+
+/************************************************************************
+ * Create strong id for TechnologyDevice to avoid illegal type casting 
+ ***********************************************************************/
+#ifndef TECHNOLOGY_LIBRARY_FWD_H
+#define TECHNOLOGY_LIBRARY_FWD_H
+
+#include "vtr_strong_id.h"
+
+struct technology_device_id_tag;
+struct technology_variation_id_tag;
+
+typedef vtr::StrongId<technology_device_id_tag> TechnologyDeviceId;
+typedef vtr::StrongId<technology_variation_id_tag> TechnologyVariationId;
+
+/* Short declaration of class */
+class TechnologyLibrary;
+
+#endif