Self healing materials... How do you choose an inital state?
Where do you start with a self healing material? In my mind you have to consider the initial state in order to find a way back to it. From there you will need to find material and move that material. These processes will all require energy from somewhere.
The human body has all these systems in place.
Are we even able to plug a hole with what we have now?
The healing process in a self-healing materials happened through diffusion mass transfer and chemical binding. The process is an inter-facial process.The self-healing systems do not require any manual intervention or additional external stimulus (heating, mechanical force, light) for the self-healing event to take place (autonomous) and utilize added healing agents to repair the damage (external). The healing component/agents are already part of self-healing materials and the transfer only happen, when there is external (surface) or internal (crack, dislocation). The initial state is chosen based on desired functionalities and nature of damage of the self-healing materials and the healing materials based on their physical and chemical characteristics.
- Ying Yang, Xiaochu Ding, Marek W. Urban. Chemical and physical aspects of self-healing materials. Progress in Polymer Science, 2015; 49–50: 34-59.
- A. Cuvellier, A. Torre-Muruzabal, G. Van Assche, K. De Clerck, H. Rahier. Selection of healing agents for a vascular self-healing application. Polymer Testing, 2017; 62: 302-310.
- Xiangyu Yin, Zhilu Liu, Daoai Wang, Xiaowei Pei, Bo Yu, Feng Zhou. Bioinspired Self-Healing Organic Materials: Chemical Mechanisms and Fabrications. Journal of Bionic Engineering, 2015; 12 (1): 1-16
Another good reference are the folks at Biomimicry 3.8 who run Ask Nature.
Most of my experience in the field has been with self polymerizing organics, that reform bonds even after being physically disrupted...think Chia Mucilage (goo) and similar organic polymers.
A brief discussion on inorganic self healing material:
Materials in gel-state, composed of cross-linked polymers, are technically more versatile for use in self-healing technology. The key factor in self-healing is reversibility and crosslinking ability of the chemical bonds in the polymeric molecules forming the material.  One of the important parameter in determining extent of self-healing is E-modulus achieved at higher temperatures that may allow reversible bond opening and exchange reactions.  Preparation of non-polymeric self-healing material is desirable, however this remains to be realized. So at present for most cases the initial state of self healing material mostly involves polymeric gel. 
 Nakahati, M. et al. Self-Healing Materials Formed by Cross-Linked Polyrotaxanes with Reversible Bonds. Chem 2017, 1 (5), 766-775.
 Zechel, S. et al. Intrinsic self-healing polymers with a high E-modulus based on dynamic reversible urea bonds. NPG Asia Materials 2017, e420.
 Li, J. et al. Self-Healable Gels for Use in Wearable Devices. Chem. Mater. 2017, 29 (21), 8932–8952.