Review · Touch
From mechanics to data: how research on robotic touch has changed

THE FINDING
Touch tells a robot directly what is happening where it makes contact, which makes it central to dexterous manipulation. This review traces the shift from reading tactile signals through contact mechanics to learning representations and policies from data, with imitation learning, reinforcement learning, VLA models and predictive models.
Read with two questions in mind: which action decisions change with touch, and do those decisions carry over to unfamiliar objects?
QUESTION
The problem · contact changes the information
Before grasping, location matters. Afterward, the question changes to what is happening within the grasp. Imagine moving a transparent cup: seeing it does not by itself reveal whether contact is secure or the cup is beginning to tilt. A useful reading starts by locating the missing information at each stage of an action. That gives a tactile sensor a specific role rather than treating it as an extra sense added for its own sake.
APPROACH
The approach · mechanics and data
The review covers mechanics-based interpretation and learning representations or policies from data, including imitation learning, reinforcement learning, VLA and predictive models. An editorial way to organize the material is to separate sensor input, internal representation and resulting action. Ask which connection a particular method studies. The two perspectives need not be read as completely replacing one another.
LIMITS
Scope · compare sensing and control together
A review maps approaches; it is not a ranking from one shared experiment. An editorial comparison should record the observed quantity, objects, action adjustment and completion criterion together. A clearer signal and a better task outcome are also different findings. Look for the connection showing how improved observation changed what the robot could do.
MAKE IT CONCRETE
An imagined grasp of cloth
Imagine grasping a corner of cloth before folding it. Vision identifies a candidate; the hand approaches and makes contact. If the cloth does not follow, the system must decide whether to retry, adjust or continue. Saving another image is not itself the solution: the observation needs to change a choice. This is an editorial example for connecting sensing with action, not a reported experiment from the reviewed paper.

