Monolithic solder-on nanoporous Si-Cu contacts for stretchable silicone composite sensors

We report a method of creating solderable, mechanically robust, electrical contacts to interface (soft) silicone-based strain sensors with conventional (hard) solid-state electronics using a nanoporous Si-Cu composite. The Si-based solder-on electrical contact consists of a copper-plated nanoporous Si top surface formed through metal-assisted chemical etching and electroplating, and a smooth Si bottom surface which can be covalently bonded onto silicone-based strain sensors through plasma bonding. We investigated the mechanical and electrical properties of the contacts proposed under relevant ranges of mechanical stress for applications in physiological monitoring and rehabilitation. We also produced a series of proof-of-concept devices, including a wearable respiration monitor, leg band for exercise monitoring and Squeeze-ball for monitoring rehabilitation of patients with hand injuries or neurological disorders, to demonstrate the mechanical robustness and versatility of the technology developed, in real-world applications

Autocatalytic metallization of fabrics using Si ink, for biosensors, batteries and energy harvesting

Commercially available metal inks are mainly designed for planar substrates (for example, polyethylene terephthalate foils or ceramics), and they contain hydrophobic polymer binders that fill the pores in fabrics when printed, thus resulting in hydrophobic electrodes. Here, a low‐cost binder‐free method for the metallization of woven and nonwoven fabrics is presented that preserves the 3D structure and hydrophilicity of the substrate. Metals such as Au, Ag, and Pt are grown autocatalytically, using metal salts, inside the fibrous network of fabrics at room temperature in a two‐step process, with a water‐based silicon particle ink acting as precursor. Using this method, (patterned) metallized fabrics are being enabled to be produced with low electrical resistance (less than 3.5 Ω sq−1). In addition to fabrics, the method is also compatible with other 3D hydrophilic substrates such as nitrocellulose membranes. The versatility of this method is demonstrated by producing coil antennas for wireless energy harvesting, Ag–Zn batteries for energy storage, electrochemical biosensors for the detection of DNA/proteins, and as a substrate for optical sensing by surface enhanced Raman spectroscopy. In the future, this method of metallization may pave the way for new classes of high‐performance devices using low‐cost fabrics

Stretchable Composite Acoustic Transducer for Wearable Monitoring of Vital Signs

A highly flexible, stretchable, and mechanically robust low-cost soft composite consisting of silicone polymers and water (or hydrogels) is reported. When combined with conventional acoustic transducers, the materials reported enable high performance real-time monitoring of heart and respiratory patterns over layers of clothing (or furry skin of animals) without the need for direct contact with the skin. The approach enables an entirely new method of fabrication that involves encapsulation of water and hydrogels with silicones and exploits the ability of sound waves to travel through the body. The system proposed outperforms commercial, metal-based stethoscopes for the auscultation of the heart when worn over clothing and is less susceptible to motion artefacts. The system both with human and furry animal subjects (i.e., dogs), primarily focusing on monitoring the heart, is tested; however, initial results on monitoring breathing are also presented. This work is especially important because it is the first demonstration of a stretchable sensor that is suitable for use with furry animals and does not require shaving of the animal for data acquisition

Disposable silicon-based all-in-one micro-qPCR for rapid on-site detection of pathogens

cycle. Using TriSilix, we also detect the cDNA from SARS-CoV-2 (1 pg) with high specificity against SARS-CoV (2003)

Stretchable composite acoustic transducer for wearable monitoring of vital signs

A highly flexible, stretchable, and mechanically robust low‐cost soft composite consisting of silicone polymers and water (or hydrogels) is reported. When combined with conventional acoustic transducers, the materials reported enable high performance real‐time monitoring of heart and respiratory patterns over layers of clothing (or furry skin of animals) without the need for direct contact with the skin. The approach enables an entirely new method of fabrication that involves encapsulation of water and hydrogels with silicones and exploits the ability of sound waves to travel through the body. The system proposed outperforms commercial, metal‐based stethoscopes for the auscultation of the heart when worn over clothing and is less susceptible to motion artefacts. The system both with human and furry animal subjects (i.e., dogs), primarily focusing on monitoring the heart, is tested; however, initial results on monitoring breathing are also presented. This work is especially important because it is the first demonstration of a stretchable sensor that is suitable for use with furry animals and does not require shaving of the animal for data acquisition

Desarthrodesis and prosthetic reconstruction of the knee after resection of bone tumors.

Background and Objectives: The aim of the present study was to review the long-term results in patients who had undergone modular prosthetic reconstruction of the knee, following a failed arthrodesis performed after the resection of bone tumors. Methods We reviewed 16 desarthrodeses and prosthetic reconstructions of the knee following a failed artificial arthrodesis after bone tumor resection. Desarthrodeses and subsequent knee megaprosthesis were performed after breakage of the arthrodesis implant in 11 cases and following presumed eradication of infection in five cases. Results The mean follow-up was 15.9 years. The mean post-operative range of knee flexion was 70\ub0, but only four patients had active extension of the knee. Functional results, according to the MSTS system, were satisfactory in 11 patients. Complications included deep infections in five patients, aseptic loosening in three patients, breakage of the joint hinge in one patient, and patellar tendon avulsion in one patient. Despite a high rate of complications, all but two patients were satisfied. Conclusion Our findings indicate that conversion of oncological knee arthrodesis to total knee arthroplasty should be taken into consideration only after giving the patient extensive information about the high risk of serious complications

Disposable silicon-based all-in-one micro-qPCR for rapid on-site detection of pathogens

Rapid screening and low-cost diagnosis play a crucial role in choosing the correct course of intervention when dealing with highly infectious pathogens. This is especially important if the disease-causing agent has no effective treatment, such as the novel coronavirus SARS-CoV-2, and shows no or similar symptoms to other common infections. Here, we report a disposable silicon-based integrated Point-of-Need transducer (TriSilix) for real-time quantitative detection of pathogen-specific sequences of nucleic acids. TriSilix can be produced at wafer-scale in a standard laboratory (37 chips of 10 × 10 × 0.65 mm in size can be produced in 7 h, costing ~0.35 USD per device). We are able to quantitatively detect a 563 bp fragment of genomic DNA of Mycobacterium avium subspecies paratuberculosis through real-time PCR with a limit-of-detection of 20 fg, equivalent to a single bacterium, at the 35th cycle. Using TriSilix, we also detect the cDNA from SARS-CoV-2 (1 pg) with high specificity against SARS-CoV (2003)

Desarthrodesis and prosthetic reconstruction of the knee after resection of bone tumors.

Background and Objectives: The aim of the present study was to review the long-term results in patients who had undergone modular prosthetic reconstruction of the knee, following a failed arthrodesis performed after the resection of bone tumors. Methods We reviewed 16 desarthrodeses and prosthetic reconstructions of the knee following a failed artificial arthrodesis after bone tumor resection. Desarthrodeses and subsequent knee megaprosthesis were performed after breakage of the arthrodesis implant in 11 cases and following presumed eradication of infection in five cases. Results The mean follow-up was 15.9 years. The mean post-operative range of knee flexion was 70\ub0, but only four patients had active extension of the knee. Functional results, according to the MSTS system, were satisfactory in 11 patients. Complications included deep infections in five patients, aseptic loosening in three patients, breakage of the joint hinge in one patient, and patellar tendon avulsion in one patient. Despite a high rate of complications, all but two patients were satisfied. Conclusion Our findings indicate that conversion of oncological knee arthrodesis to total knee arthroplasty should be taken into consideration only after giving the patient extensive information about the high risk of serious complications