Quantity   Component name
2 × Thermoelectric generator peltier size 40mm If you are making flashlight then you need two peltiers and for headlamp you need 4 peltiers
1 × volt boosting circuit from txl group https://customthermoelectric.com/elc-vb0410-1-unipolar-voltage-booster-40mv.html
1 ×  Acrylic Sheet Covered on Aluminum pipe leaving area of peltier 40mm local made
1 ×  Aluminum Rectangle pipe used for heat sink Aluminium rectangle pipe should be like heat sink. And For head lamp your need 4 heat sink
1 × 8mm 0.28W Strawhat White LED if you use 1 watt LED with having very smaller yellow dot that bright in LED.