'Don't swallow it — wear it': Korean researchers develop smartphone-controlled electronic pain patch

"Every time pain flares up, you can deal with it just by sticking something on your skin — no need to take a painkiller."

Korean researchers have developed a wearable electroceutical patch that can be operated remotely via smartphone and automatically delivers electrical stimulation when it detects changes in the body's condition. Once validated through clinical trials, the technology could allow chronic pain patients to receive personalized pain management without visiting a hospital.

KAIST announced Sunday that a joint research team led by Professor Jeong Jae-woong of the Department of Electrical Engineering and Lee Sang-hoon of the Korea Institute of Oriental Medicine had developed a wearable electroceutical platform combining wireless microneedle technology with Internet of Things remote-control capabilities.

Painkillers are widely used to treat chronic pain, but long-term use carries risks of side effects and dependency. Opioid painkillers used for conditions such as cancer pain pose growing risks of tolerance and misuse the longer they are taken. As a result, electroceuticals — devices that modulate nerves through electrical stimulation rather than medication — are drawing attention as a new alternative.

Existing electroceuticals, however, have their own limitations. Implantable devices require surgery and carry risks of infection and complications. Skin-adhesive devices can deliver unstable electrical stimulation depending on skin conditions such as sweat, sebum and dead skin cells. When current concentrates in a specific area, there is also a risk of overheating or burns.

To address these problems, the research team developed temperature-responsive conductive and adhesive microneedle electrodes that penetrate the stratum corneum, the outermost layer of skin.

The tiny needles pass through the stratum corneum — which has high electrical resistance — to deliver stable electrical stimulation regardless of changes in skin condition. The electrodes are coated with a conductive hydrogel so that current spreads evenly rather than concentrating at the needle tips.

A safety mechanism was also built in: if skin temperature rises abnormally, the electrode's adhesion weakens and it detaches from the skin on its own.

The team also connected the device to a smartphone and cloud server. Patients can operate it themselves, and medical staff can control the timing and activation of electrical stimulation in real time or on a scheduled basis from a remote location. The team confirmed that remote operation works even across long distances, such as between South Korea and the United States.

The device also incorporates a self-monitoring function. A photoplethysmography sensor analyzes changes in pulse and blood flow to detect stress states associated with pain, then automatically applies electrical stimulation.

The research demonstrates the potential for automated, personalized pain management without requiring the user to manually switch the device on or adjust stimulation intensity each time.

In animal experiments, the device delivered current more effectively than conventional gel electrodes and showed a pain-relieving effect. A small-scale preliminary study in healthy adults also confirmed that skin sensation and pain thresholds changed after remotely scheduled electrical stimulation was applied.

However, the treatment's effectiveness in actual pain patients has not yet been established. The human study was a preliminary validation conducted on healthy adults, and further clinical research is needed to confirm therapeutic effects and long-term safety in chronic pain patients.

"There is potential for use in cases requiring repeated management, such as peripheral neuropathy pain following cancer treatment or musculoskeletal pain in older adults," said KAIST Professor Jeong Jae-woong. "It could also be applied to non-drug treatment of other conditions where nerve modulation through electrical stimulation is beneficial, as well as digital healthcare and home medical care settings that require remote management by medical staff."

Lee Sang-hoon of the Korea Institute of Oriental Medicine said he hoped the research would eventually merge with wearable acupuncture technology to advance a new non-pharmacological pain management approach that stimulates acupoints through electrical stimulation.

The findings were published in Nature Communications.