Hari Prakash Thanabalan

Inchworm-Inspired Soft Robot with Groove-Guided Locomotion on ArXiv

Photograph of the soft robot, consisting of a multilayer rolled dielectric elastomer actuator integrated with a
flexible PET sheet. *(Image by H. P. Thanabalan.)*

Inchworm-Inspired Soft Robot with Groove-Guided Locomotion
Hari Prakash Thanabalan, Lars Bengtsson, Ugo Lafont, Giovanni Volpe
arXiv: 2512.07813

Soft robots require directional control to navigate complex terrains. However, achieving such control often requires multiple actuators, which increases mechanical complexity, complicates control systems, and raises energy consumption. Here, we introduce an inchworm-inspired soft robot whose locomotion direction is controlled passively by patterned substrates. The robot employs a single rolled dielectric elastomer actuator, while groove patterns on a 3D-printed substrate guide its alignment and trajectory. Through systematic experiments, we demonstrate that varying groove angles enables precise control of locomotion direction without the need for complex actuation strategies. This groove-guided approach reduces energy consumption, simplifies robot design, and expands the applicability of bio-inspired soft robots in fields such as search and rescue, pipe inspection, and planetary exploration.

Hari Prakash received the Best Early-Career Researcher Presentation Award at ETAI 2025, San Diego

Hari Prakash received the Best Early Career Researcher Presentation Award at Emerging Topics in Artificial Intelligence (ETAI) 2025 held in San Diego, from 3 to 7 August 2025.

The award, which includes a certificate, a cash prize of $300, and a T-shirt, is presented by the organisers of the conference in collaboration with SPIE Optics + Photonics.

Hari was awarded the prize for his presentation titled “Inchworm-Inspired Soft Robot with Groove-Guided Locomotion”. Below is the full abstract of her presentation:

Presentation by H. P. Thanabalan at SPIE-ETAI, San Diego, 5 August 2025

Inchworm-inspired soft robot. *(Image by H. P. Thanabalan.)*

Bio-inspired soft robot for multi-directionality
Hari Prakash Thanabalan, Lars Bengtsson, Ugo Lafont, Giovanni Volpe
SPIE Optics+Photonics, San Diego, CA, USA, 3-7 August 2025
Date: 5th August 2025
Time: 8:30 AM – 8:45 AM
Place: Conv. Ctr. Room 4

Soft robotics are the forefront of robotics evolution that leverages compliant materials such as silicone elastomer to mimic biological organisms. With infinite degrees of freedom, soft robots surpass rigid robots in adaptability making them ideal for exploration and manipulation tasks. Here we focus on inchworm inspired soft robot achieving multidirectional locomotion through groove-guided movement. By manipulating the groove angles on a substrate, we demonstrate multidirectional locomotion by utilising only a single actuator.

Hari Prakash presented his half-time seminar on 10th June 2025

Half-time seminar in Nexus, with Prof. Bernhard Mehlig (examiner) and soft matter group. *(Photo by A. Callegari.)*

Hari Prakash completed the first half of his doctoral studies and he defended his half-time on the 10th of June 2025.

The presentation titled “Soft Robotic Platforms for Variable Conditions : From Adaptive Locomotion to Space Exploration” was held in hybrid form, both with part of the audience in Nexus room and through Zoom. The half-time consisted of a presentation about his past and planned projects, followed by a discussion and questions proposed by his opponent, Professor Bernhard Mehlig.

The presentation started with a short background introduction to soft robotics and bio-inpired soft robotics, followed by soft actuators used in the field of soft robotics and focused on the soft actuator used throughout his projects. He further then proceeded to introduce his first project and paper (which is under preparation) , “Inchworm-Inspired Soft Robot with Groove-Guided Locomotion,” and finally proceeded to introduce his second project “Soft Inchworm-Inspired Robot Fault-Tolerant Artificial Muscles for Planetary Exploration – Simulation of fault-tolerant artificial muscles under proton, neutron, and alpha irradiation”, a project in collaboration with the European Space Agency (ESA).

In the last section, he outlined the proposed continuation of his PhD: Experimental and the development of inchworm inspired soft robot for space exploration, particularly the Martian environment, testing the robot under real proton, neutron and alpha irradiation, quantification and characterisation of the robot under space radiation.

Space Slam Event – Visit by Marcus Wandt, Sweden’s third astronaut and Chalmers alumnus

Group picture of the participants to the Space Slam event. *(Image provided by R. Cumming)*

On Tuesday 9th April 2024, the event called “Space Slam” took place at Chalmers University.

Here, young researchers get to present exciting space-related work they have been or are doing at Chalmers / Gothenburg University – in one or two minutes, with the help/support of a picture and/or a prop. This event was participated by Marcus Wandt, Sweden’s third astronaut.

In this event, Hari presented his topic titled “Annelid inspired soft robot for planetary exploration” where this project is in collaboration with the European Space Agency (ESTEC-ESA) and Gothenburg University.