Taxel
How it works
Each taxel is a transducer that converts the local normal force or pressure into an electrical signal — a change in capacitance, resistance, piezoelectric charge, or (in optical sensors) a surface deformation observed by a camera. Taxels are arranged in a regular grid and read out via matrix (row–column) addressing or dedicated signal routing, sampling the value of every cell. The combined readings of all taxels form a tactile frame that the robot's perception stack then processes. Taxel density sets the spatial resolution, while the transducer's properties set the force range and sensitivity.
Problem solved
A single force sensor reports only one aggregate value and cannot localize or image the shape of a contact. Taxels solve this by distributing the measurement across many points, yielding a spatial pressure map needed to detect edges, slip and grasp stability.
Components
The individual cell that converts local normal force or pressure into a measurable signal (capacitive, piezoresistive, piezoelectric or optical). This is the taxel proper.
Official
The row/column (or dedicated-trace) wiring that addresses individual taxels and reads their values, assembling them into a tactile image frame.
Official
Evolution
Wu, Wen and Wang demonstrated a matrix of vertical-nanowire piezotronic transistors in which each taxel is individually addressable, enabling active and adaptive tactile imaging (Science).
Hyperparameters (configurable axes)
Number of taxels per unit area and the pitch between them; determines how finely contact detail can be resolved.
Smallest detectable force and the range of pressures a single taxel can measure.
Total number of taxels and the array geometry covering a given surface.
Sensing mechanism: capacitive, piezoresistive, piezoelectric or optical — affects sensitivity, durability and readout.