##  [Fick's Laws of Diffusion](/ficks-laws-diffusion) 

  ##  [Fick's Laws of Diffusion](https://health.quantumdictionary.io/ficks-laws-diffusion-0) 

  

 [![Health & Life Sciences Dictionary](/sites/default/files/styles/large/public/2026-01/Health%20%26%20Life%20Sciences.png.webp?itok=yyyaiQOY)](/topic-specific-dictionaries/health-life-sciences)



**Health & Life Sciences Dictionary**

 







 

 

 

 



 

 

 

 

Definition

Two continuum relations describing molecular or ionic transport driven by concentration differences: Fick's first law gives steady-state diffusive flux J = −D∇c (flux proportional to the spatial concentration gradient and the diffusion coefficient D); Fick's second law gives time-dependent concentration change ∂c/∂t = D∇²c for homogeneous, constant-D media (or its generalized form when D varies sp