Single-process 3D-printed smart pad with CNN-based touch localization and force classification

Barši Palmić, Tibor (avtor), Podlipnik, Enej (avtor), Slavič, Janko (avtor)

Multi-material 3D-printing enables the single-process embedding of piezoresistive sensors producing multi-functional, fully 3D-printed, smart structures without manual assembly or specialized equipment. However, the low sensitivity and manufacturing variability yield unreliable signals, limiting 3D-printed sensors to simple demonstrations rather than complex sensing tasks. This work introduces a single-process, 3D-printed structure with inherently poor sensing capability that is transformed into a highly accurate smart pad with functional tap localization using a convolutional neural network (CNN). The structure consists of a thermoplastic polyurethane (TPU) pad with up to four embedded piezoresistive sensors fully fabricated through material extrusion (MEX). The CNN processes measured time-series signals to predict the tap location and classify the force magnitude. The 4-sensor smart pad reliably distinguishes individual taps with millimeter accuracy (3.56 mm mean accuracy), enabling touch-pad applications with force classification (>98.7% accuracy). The single-sensor smart pad maintains functional performance (6.32 mm mean accuracy), proving that machine learning compensates for the extreme sensor reduction. This work establishes a rapid-prototyping platform for application-specific CNN-enhanced smart structures in human-machine interfaces, soft robotics, and structural health monitoring.

• Jezik: Angleški jezik
• Ključne besede: multi-material 3D-printing, smart structures, piezoresistive sensors, convolutional neural networks, impact detection
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2026
• Št. strani: 15 str.
• Številčenje: Vol. 21, no. 1, art. e2640277
• PID: 20.500.12556/RUL-181418
• UDK: 681.586:004.92
• ISSN pri članku: 1745-2759
• DOI: 10.1080/17452759.2026.2640277
• COBISS.SI-ID: 274318851
• Datum objave v RUL: 07.04.2026

Gradivo je del revije

• Naslov: Virtual and physical prototyping
• Založnik: Taylor & Francis
• ISSN: 1745-2759
• COBISS.SI-ID: 514087705

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: 3D-tisk z zaznavali, pametne strukture, piezorezistivni senzorji, konvolucijske nevronske mreže, zaznavanje trka, procesiranje signalov, strojno učenje

Projekti

• Financer: ARIS - Javna agencija za znanstvenoraziskovalno in inovacijsko dejavnost Republike Slovenije
• Številka projekta: P2-0263
• Naslov: Mehanika v tehniki

• Financer: ARIS - Javna agencija za znanstvenoraziskovalno in inovacijsko dejavnost Republike Slovenije
• Številka projekta: L2-60140
• Naslov: Aktivni samozavedni 3D-tiskani dinamski sistemi in strukture