Media playback is unsupported on your device Media caption I Wayan Sumardana claims to have made a bionic arm out of junk at home

When a man in a small village in Bali claimed to have made a functioning bionic arm out of scrap metal at home he became a local sensation. But even as serious doubts emerged about the technology behind it, BBC Indonesian's Christine Franciska found his fellow villagers remained enthralled by the mystical aspect of his story.

It takes two hours from the Balinese capital Denpasar to reach Nyuhtebel Village in Karangasem, the home of the man who has been dubbed "cyborg" or "Iron Man" by the local press.

I Wayan Sumardana, a 31-year-old welder in a small village in Bali, said he woke up one morning six months ago to find he had lost all feeling in his left arm.

"At first, I thought it was a light stroke, but my doctor couldn't explain what was happening. He said go to the shaman, but the shamans gave up too," he said.

He described his state of limbo after the event.

"For two months I couldn't work at all. I was stressed out. I had no money left. Then I got the idea to create this machine."

Image caption Six months ago Mr Sumardana woke up to find out that he had lost feeling in his arm

He is referring to the "bionic arm" - a robotic contraption that looks like it has been built out of scrap metal and inspired by cyborg movies.

Mr Sumardana, who is also known as Sutawan, has never been to university but he went to a technical secondary school and says he has been obsessed with electrical engineering ever since he was a child. He works as a welder and also a repairman, fixing household electronics such as fans, televisions and refrigerators.

He says he made the "bionic arm" from scrap metals, a lithium battery, gear wheels, dynamo cables and other electronic components.

His workshop, where he lives with his wife and three sons, is full of junk, scrap metal in every corner, piles of plastic bottles, a worn-out sofa, and chickens running around.

When I arrived it was filled with journalists and curious villagers. Local government officials and policemen were also there, preparing for a visit from the governor of Bali.

But his explanation of the genesis of the robotic arm combined practical technical knowledge with mysticism.

"It's like a lie detector machine," he tells me. "I send a signal from my brain and that message is captured by the machine and it makes my arm move."

"It is simple and anyone could make it and I am not brilliant," he adds.

Image caption Mr Sumardana has become a sensation in Bali for building the arm

Image caption He claims that the machine is controlled by brain signals, but experts have cast doubt on this

It is an account that a mechanical engineering expert from Udayana University in Bali, who met Mr Sumardana and saw the machine, cast doubt upon.

"When I met him the machine was broken. So I asked him how it works," Wayan Widiada explained.

"It's a robot structure but there are some important components missing. He has a mechanical and electrical structure, but it doesn't have any computer coding. How can the machine recognise a command without computer programming?"

'Signal receiver headband'

Mr Sumardana, however, says the mechanical arm has allowed him to work. In front of a crowd he demonstrated how he can fix machines wearing it.

The "bionic hand" appeared to be moving and he certainly appeared able to do his daily work with this contraption. Observing his movements closely, it is clear that while using the arm he was unable to clench his fist - but he could move his elbow and shoulder joints. Without the "robotic sleeve" his arm hangs limply by his side and he has only partial movement in three of his fingers.

There were few doubters in this crowd and he gave anyone curious - including me - a chance to try his "signal receiver headband".

"Try to concentrate, close your eyes and you will see four square lights. Try to turn on all the lights," Mr Sumardana said, as I put the device around my head.

I tried my hardest but I didn't see anything. Others who tried had the same experience.

Mr Sumardana says it is hard to make it move and he can only use it for four hours at a time. After that it makes him feel sick and dizzy.

Image caption The contraption, he says, has enabled him to continue work

The brain-signals narrative is also something experts would certainly cast doubt upon and when his story takes a mystical turn it becomes clear that Mr Sumardana is not simply a man devoted to the pursuit of science and robotics.

He says that he becomes slightly possessed when he puts on the "bionic arm".

"I am not myself," he says.

His wife, Nengah Sudiartini adds to this saying that she believes spirits played a part in her husband's problems.

"I saw this left arm was missing. But after about an hour, my son looked at my husband again and he said the arm was there. And yes, it was there, but before it wasn't. After that, he couldn't move it."

"We went to the doctors, but they couldn't explain what happened," Ms Nengah said.

The Balinese have deep spiritual and mystical beliefs and Mr Sumardana's story has certainly inspired many in the small village, who are seeing it as a tale of a man's determination to use his technical knowledge in the face of a crisis brought on by spirits.

"I don't care if it is a robot or not," said Sang Putu Wardhana, a self-employed man from Denpasar.

"For me he is extraordinary. Not many people who suffer can fight and survive."

Scientists may give his tale short shrift, but to his fellow villagers, the veracity of his claims is simply not the point.