Flexible Ultrasonic Transducer Array with Bulk PZT for Adjuvant Treatment of Bone Injury.

Flexible electronic devices are developing rapidly, especially in medical applications. This paper reports an arrayed flexible piezoelectric micromachined ultrasonic transducer (FPMUT) with a sandwich structure for adjuvant treatment of bone injury. To make the device conformable and stretchable for attaching to the skin surface, the flexible substrate of polydimethylsiloxane (PDMS) was combined with the flexible metal line interconnection between the bulk lead zirconate titanate (PZT) arrays. Simulations and experiments were carried out to verify the resonant frequency and tensile property of the reported FPMUT device. The device had a resonant frequency of 321.15 KHz and a maximum sound pressure level (SPL) of 180.19 dB at the distance of 5 cm in water. In addition, detailed experiments were carried out to test its acoustic performance with different pork tissues, and the results indicated good ultrasound penetration. These findings confirm that the FPMUT shows unique advantages for adjuvant treatment of bone injury.

The Design and Characterization of a Flexible Tactile Sensing Array for Robot Skin.

In this study, a flexible tactile sensing array based on a capacitive mechanism was designed, fabricated, and characterized for sensitive robot skin. A device with 8 × 8 sensing units was composed of top and bottom flexible polyethyleneterephthalate (PET) substrates with copper (Cu) electrodes, a polydimethylsiloxane (PDMS) dielectric layer, and a bump contact layer. Four types of microstructures (i.e., pyramids and V-shape grooves) atop a PDMS dielectric layer were well-designed and fabricated to enhance tactile sensitivity. The optimal sensing unit achieved a high sensitivity of 35.9%/N in a force range of 0-1 N. By incorporating a tactile feedback control system, the flexible sensing array as the sensitive skin of a robotic manipulator demonstrated a potential capability of robotic obstacle avoidance.

An epidermal sEMG tattoo-like patch as a new human-machine interface for patients with loss of voice.

Throat cancer treatment involves surgical removal of the tumor, leaving patients with facial disfigurement as well as temporary or permanent loss of voice. Surface electromyography (sEMG) generated from the jaw contains lots of voice information. However, it is difficult to record because of not only the weakness of the signals but also the steep skin curvature. This paper demonstrates the design of an imperceptible, flexible epidermal sEMG tattoo-like patch with the thickness of less than 10 µm and peeling strength of larger than 1 N cm-1 that exhibits large adhesiveness to complex biological surfaces and is thus capable of sEMG recording for silent speech recognition. When a tester speaks silently, the patch shows excellent performance in recording the sEMG signals from three muscle channels and recognizing those frequently used instructions with high accuracy by using the wavelet decomposition and pattern recognization. The average accuracy of action instructions can reach up to 89.04%, and the average accuracy of emotion instructions is as high as 92.33%. To demonstrate the functionality of tattoo-like patches as a new human-machine interface (HMI) for patients with loss of voice, the intelligent silent speech recognition, voice synthesis, and virtual interaction have been implemented, which are of great importance in helping these patients communicate with people and make life more enjoyable.

Efficacy and side-effects of a semi-individualized Chinese herb mixture "Tiáo Geng Tang" for menopausal syndrome in China.

BACKGROUND: Chinese herbal medicine is an alternative therapy for menopausal problems and is widely practiced in China and many other Asian countries. However, efficacies and side-effects are rarely assessed according to the standards of evidence-based medicine. PATIENTS AND METHODS: This is a prospective observatory study following efficacy and side-effects of a semi-individualized Chinese herbal mixture "Tiáo Geng Tang (TGT)" in 30 patients for 3 months. Another group of 30 patients receiving hormone therapy with tibolone was included as a positive comparison. Common questionnaire-based measuring instruments were: modified Kupperman index, menopause rating scale, life quality and Chinese medical symptom scale (CMSS). Follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) were determined before and three months after the treatments. RESULTS: Significant improvement was seen in overall scores of all the four measurements in both groups. For some symptoms, including dry mouth, tinnitus, poor appetite and constipation, TGT was more effective than tibolone. For psychosocial and sexual sub-scales of life quality, tibolone has a slightly higher remedy rate than TGT. TGT lowered FSH and LH significantly, as tibolone did, but elevated E2 significantly less than tibolone. Various adverse events, including body weight increase, abdomen discomfort, nausea/vomiting, emotional instability, pressure in breasts and dizziness, were reported by patients treated with tibolone, whereas only diarrhea was observed in two patients treated with TGT. CONCLUSION: TGT alleviates menopausal symptoms with similar efficacy as tibolone but has fewer side effects.

Bioinspired in situ growth of conversion films with underwater superoleophobicity and excellent self-cleaning performance.

Wax deposition during the production and transportation of crude oil is a global problem in oil industries. Fabrication of underwater self-cleaning materials can provide a new strategy to prohibit wax deposition. In this paper, conversion films on carbon steel with hierarchical micro/nanostructure are fabricated through a novel in situ alternating-current deposition method. The flower-like conversion films are composed of amorphous iron phosphate and present superhydrophilicity in air and superoleophobicity underwater. The conversion films can efficiently prevent the deposition of wax in water-contained crude oil, showing excellent self-cleaning performance. This facile and low-cost fabrication of a self-cleaning film provides a good strategy for underwater-oil prevention.