A 3D-Printed Programmable Porosity-Gradient Lattice for Piezoresistive Sensing with High Sensitivity and Broad Pressure Range

The intrinsic trade-off between sensitivity and pressure detection range has long plagued flexible pressure sensors. Here, a graphene/Polydimethylsiloxane (PDMS) flexible piezoresistive sensor featuring a programmable porosity-gradient lattice is developed that combines high sensitivity with a broad pressure detection range. The porosity distribution and interlayer filament arrangement are predefined in a 3D-printed sacrificial template, enabling structural regulation of the deformation sequence and interfilament contact. Graphene predeposited on the template is subsequently retained on the replicated PDMS filament surfaces, directly linking the designed lattice geometry with pressure-induced conductive-pathway evolution. The sensor exhibits an ultrahigh sensitivity of 510.2 kPa^-1, 0-16 kPa, while retaining sensitivities of 32.9 and 7.2 kPa^-1 in the ranges of 16-190 kPa and 190-500 kPa, respectively. Moreover, the sensor enables wrist-pulse monitoring, Morse-code-based tactile communication, robotic recognition of object curvature and softness, and deep-learning-assisted recognition of six beverage bottles with an accuracy of 98.89%. This work demonstrates that programming the spatial porosity distribution of a periodic lattice provides an effective route for coordinating deformation and conductive-network evolution in flexible pressure sensors with high sensitivity and a broad detection range.